Drippy, savory, amazing roast beef sandwiches with caramelized onions are my go-to whenever I'm heading to a game night with friends or going to a Friendsgiving party!
Think of these as French dip sliders; one of my favorite sandwiches, just in mini form—y’all already know I have a soft spot for anything petite (I mean, I’m 4’11”, so it feels right).
These sliders are it when I’m hosting or bringing something to a party. Soft Hawaiian rolls, gooey melted cheese, sweet caramelized onions, and the kind of rich, savory au jus that makes you want to tip the bowl straight to your mouth. I won’t judge—I’ve done it.
Jump to:
- Cheesy Baked Roast Beef Sliders on Hawaiian Rolls
- Why We Love this Roast Beef Sliders Recipe
- Ingredients Needed
- How to Make Easy Roast Beef Sliders with Caramelized Onions
- Chef's Tips and Recipe Variations
- Recipe Variations
- Make Ahead Tips
- Equipment I Used
- Frequently Asked Questions
- More Sandwiches and Sliders You'll Love
- Buttery Roast Beef Sliders with Caramelized Onions
Cheesy Baked Roast Beef Sliders on Hawaiian Rolls
These sliders are a full-on situation in the best way. We’re talking caramelized onions, a from-scratch aioli, and a rich au jus that pulls it all together.
It’s not difficult, but it’s the kind of recipe that takes a little time and a little love.
Yes, it takes a little more love than your average slap-it-together sandwich—but honey, we’re not making average food over here.
I’ve definitely taken the long route before—slow-roasting the beef with the onions like I do for my French dip sandwiches—but that’s a three-hour affair.
This version skips the long roast, keeps the flavor, and still gets you something rich, cheesy, and absolutely worth the time it takes.
Why We Love this Roast Beef Sliders Recipe
- No dry roast beef here. We warm the beef gently so it stays juicy, not tough or overcooked—just tender and flavorful, the way it should be.
- Caramelized onions done right. Low, slow, and golden. None of that rushed, half-sautéed stuff. These bring real flavor.
- That garlic aioli is the secret weapon. Creamy, rich, and just the right amount of garlicky—it melts into every layer and makes everything taste incredible.
- No soggy bottoms. The rolls get lightly toasted from the inside out, and the cheese acts like a little barrier to keep things just right.
- Savory, buttery topping. Brushed with an herb butter that crisps up in the oven, giving the tops that golden, crave-worthy finish.
- Made for sharing (but you might not want to). Whether it’s a party, game day, or a family game night dinner, these sliders always get devoured.
Ingredients Needed
For the Caramelized Onions
- Sweet onions – These cook down low and slow into golden, jammy goodness with deep, rich flavor. Yellow or Vidalia are perfect here.
- Brown sugar – Just a touch helps speed along caramelization and brings out the natural sweetness in the onions.
- Salted Butter – The foundation. It gives the onions a luscious richness as they cook.
- Kosher salt and black pepper – Essential seasoning to balance that sweetness and bring out all the savory notes.
- Beef broth – A splash at the end adds depth and a little something savory that makes these onions feel like they were cooked in a steakhouse kitchen.
For the Garlic Aioli
- Egg yolk – This is your base—it’s what gives the aioli that silky, luxurious texture.
- Dijon mustard – Helps emulsify the sauce and brings a little zing to balance out the richness.
- Fresh garlic – Grated fine for max flavor. It’s bold and punchy in the best way.
- Lemon juice – Brightens everything up and cuts through the richness.
- Light olive oil or neutral oil – Use something mild so the garlic can shine. This gets drizzled in slowly to make a thick, creamy emulsion.
- Kosher salt – Just enough to wake everything up and round out the flavors.
For the Sliders + Garlic Butter Sauce
- Thinly sliced roast beef – Sliced deli roast beef works great, but if you’ve got leftover roast beef or want to make your own from scratch, go for it. It’s gotta be tender and flavorful, though—this is the star of the show.
- Slider buns – Sweet Hawaiian rolls are soft, just a little sweet, and hold everything beautifully. You’ll use the whole sheet of rolls—no splitting or separating.
- Melty cheese slices – Provolone cheese, swiss cheese, muenster, havarti—take your pick. Then top it off with a handful of shredded mozzarella for that extra gooey cheese pull.
- Poppy seeds + sesame seeds – They add a little texture and a nutty, toasty flavor to the tops. That poppy seed crackle? Chef’s kiss.
- Melted butter – This is what makes the tops golden, crisp, and extra flavorful.
- Garlic powder + dried minced onion (or onion powder) – These pantry MVPs add savory aroma and depth to the garlic butter sauce.
For the Au Jus
- Better Than Bouillon Beef Base – Way more flavor than regular broth. You can control how intense it gets and it brings a rich, beefy depth.
- Beef fat or butter – If you’ve got leftover beef drippings, use them! If not, butter still gives it that silky, savory richness.
- Worcestershire sauce – Adds complexity, umami, and a little tang that rounds out the whole dipping experience.
How to Make Easy Roast Beef Sliders with Caramelized Onions
Step 1 | Make the caramelized onions. Melt the butter and oil in a skillet over medium-low heat, then toss in your thinly sliced sweet onions with a pinch of salt. Let them cook low and slow, stirring occasionally, until they’re soft, golden, and jammy—about 35 to 45 minutes. Add a splash of beef broth near the end to deepen the flavor and deglaze the pan.
Step 2 | Whip up the garlic aioli. In a small bowl or blender, whisk together the egg yolk, Dijon, grated garlic, and lemon juice until smooth. While whisking constantly (or with the blender running), slowly stream in the oil until it thickens into a creamy aioli. Season with salt to taste and set it aside.
Step 3 | Prepare the au jus.
Melt butter in a medium saucepan over medium heat. Stir in the Better Than Bouillon beef base, Worcestershire sauce, and beef fat or more butter if using. Let it simmer and reduce for 15–20 minutes until it darkens and the flavor deepens. It’ll thicken slightly as it cools—perfect for dipping.
Step 4 | Toast the buns.
Preheat your oven to 350°F. Slice the Hawaiian rolls in half horizontally (keep them together in one sheet), and place the bottom half cut-side up on a baking sheet. Brush with a little melted butter and toast for about 5 minutes, just until golden.
Step 5 | Assemble the sliders.
Spread a generous layer of garlic aioli on the toasted bottom buns. Layer the roast beef slices on the buns, and I mean really pile it on -- 2 to 3 slices per slider so each one feels hearty and loaded.
Step 6 | Add the cheese and onions. Layer your slices of cheese on top of the roast beef, then top with a sprinkle of shredded mozzarella for extra melt. Top with caramelized onions for sweet, savory magic.
Step 7 | Butter and bake. Place the top buns on, then brush your garlic butter sauce on top of the buns. Don’t hold back—this is what gives the sliders that glossy, golden look. Sprinkle on poppy and sesame seeds for texture and flavor.
Step 8 | Bake and serve. Bake your roast beef sliders in the oven for 15–20 minutes, until the tops are beautifully golden brown and the cheese is melted and gooey. Slice between the rolls to separate, and serve hot with warm au jus for dipping.
Chef's Tips and Recipe Variations
- Take your time with the onions. Don’t rush 'em—caramelized onions need low heat and patience to get that deep, golden color and sweet flavor. Stir occasionally, turn the heat down if they’re browning too fast, and let them do their thing.
- Room temp ingredients are your friend. When making the aioli, make sure your egg yolk and lemon juice are at room temperature. It helps everything emulsify smoothly—no splitting, no fuss.
- Don’t skip the butter brush. That garlic-herb butter on top is what gives you that golden finish and savory flavor on the rolls. Be generous!
- Make it ahead (a little). The onions and aioli can both be made in advance. Just warm the onions slightly before assembling so they’re easier to spread and won’t cool down the rest of the sandwich.
- Au jus not thickening? No worries. It’s meant to be thin and brothy. But if it’s not reducing after 15–20 minutes, turn the heat up just a bit to help it along. It’ll deepen in color and flavor as it cooks down.
Recipe Variations
- Add a little heat. If you love a kick, swap the aioli for creamy horseradish or a spicy horseradish mayo. It cuts right through the richness and wakes everything up.
- Earthy + savory. Sauté some mushrooms until golden and add them to the beef layer. It gives everything a deep, umami vibe that pairs beautifully with the onions.
- Switch up the buns. Hawaiian rolls are a go-to, but pretzel buns add a salty edge, and dinner rolls work great too. You can even make these gluten-free if needed.
- Try a different sauce. Garlic aioli is classic here, but Dijon mustard or even a little spicy sriracha mayo will switch things up without a lot of effort.
Make Ahead Tips
- Caramelized onions can be made in advance. Honestly, they’re even better the next day. Make them up to 3 days ahead and keep them in an airtight container in the fridge. Warm them up a bit before layering onto the sliders so they spread easily and don’t cool everything down.
- Whip up the aioli a day or two ahead. Store it in the fridge in a sealed jar or container. It’ll keep for about 3–4 days, and the flavors get even better with a little time to hang out.
- Assemble ahead—but wait to bake. You can build the sliders a few hours in advance, cover the whole tray tightly with foil, and pop them in the fridge. Just hold off on brushing the butter on top until you’re ready to bake. Then brush, bake, and serve hot.
- Au jus is freezer-friendly. You can make the jus ahead and refrigerate it for a few days, or freeze it for up to a month. Just warm it up on the stove before serving.
Equipment I Used
Frequently Asked Questions
Au jus” just means “with juice”—a rich, savory sauce made from beef drippings. Since we’re not roasting our own beef here, we’re using beef base to bring that deep, slow-cooked flavor without the wait.
A quick toast on the bottom buns helps a lot—it gives them a little barrier so they don’t soak up too much moisture. And don’t skip the cheese layer—it acts like a melty little shield between the beef and the bread.
Plan on 2–3 sliders per person if you're serving them with sides or as part of a bigger spread.
If these are the main event and folks are hungry? Go ahead and count on 3–4 per person—especially if you're feeding teenagers or game day guests.
Let any leftovers cool completely, then wrap them tightly or store in an airtight container in the fridge for up to 3 days.
To reheat, cover them loosely with foil and warm in a 350°F oven for 10–15 minutes until heated through. The foil keeps the tops from getting too dark while everything gets warm and melty again.
More Sandwiches and Sliders You'll Love
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Buttery Roast Beef Sliders with Caramelized Onions
Ingredients
For the Caramelized Onions
- 2 tablespoons unsalted butter
- 1 tablespoon olive oil
- 3 large yellow onions, thinly sliced
- ½ teaspoon kosher salt
- 1 teaspoon brown sugar, optional, helps speed up caramelization
- 2 tablespoons beef broth, for deglazing
For the Homemade Garlic Aioli
- 1 large egg yolk, room temperature
- 1 teaspoon Dijon mustard
- 1 garlic clove, finely grated or minced
- 1 tablespoon fresh lemon juice
- ½ cup light olive oil or neutral oil
- Kosher salt, to taste
For the Au Jus Sauce
- ¼ cup unsalted butter
- 1 tablespoon Better than Bouillon Beef Base
- 2 cups beef broth
- 2 teaspoons Worcestershire sauce
For the Roast Beef Sliders
- 12 slider buns, sliced in half (Hawaiian rolls, preferred)
- ¼ cup homemade garlic aioli or mayonnaise
- ½ pound deli roast beef, thinly sliced
- 12 slices melty cheese, like provolone, Swiss, or muenster
- ½ cup shredded mozzarella cheese
- 2 cups caramelized onions
For the Garlic Butter Sauce
- 6 tablespoons unsalted butter, melted
- 1 teaspoon Worcestershire sauce
- 1 tablespoon poppy seeds
- 1 tablespoon white sesame seeds
- ½ tablespoon garlic powder
- ½ tablespoon dried minced onion
- ½ teaspoon kosher salt and freshly cracked black pepper
Instructions
Make the Caramelized Onions
- Melt the butter and olive oil in a large skillet over medium-low heat.2 tablespoons unsalted butter, 1 tablespoon olive oil
- Add the sliced onions, sprinkle in the salt and brown sugar, and cook low and slow, stirring occasionally, until the onions are soft, deep golden brown, and jammy — about 35–45 minutes. Stir in the beef broth at the end to deglaze the pan and pick up all that good flavor. Set aside.3 large yellow onions, ½ teaspoon kosher salt, 1 teaspoon brown sugar, 2 tablespoons beef broth
Make the Garlic Aioli
- In a small bowl, whisk together the egg yolk, Dijon mustard, grated garlic, and lemon juice until smooth.1 large egg yolk, 1 teaspoon Dijon mustard, 1 garlic clove, 1 tablespoon fresh lemon juice
- While blending with an immersion blender or using a whisk, slowly stream in the oil until the mixture thickens into a creamy aioli. Season with a pinch of salt and set it aside. (If you’re using mayo instead for an easier version, just stir in the garlic, mustard, lemon, and salt!)½ cup light olive oil or neutral oil, Kosher salt
Get the Au Jus Started
- Melt the butter in a medium saucepan over medium heat. Stir in the Better than Bouillon beef base, beef broth, and Worcestershire sauce. Let it simmer for 15–20 minutes until it reduces by about half. It’ll darken slightly and thicken a little as it cools. Keep warm for serving.¼ cup unsalted butter, 1 tablespoon Better than Bouillon Beef Base, 2 cups beef broth, 2 teaspoons Worcestershire sauce
Toast the Bottom Buns
- Preheat your oven to 350°F (180℃ or Gas Mark 5)
- Slice the buns in half horizontally without separating them. Place the bottom buns, cut-side up, on a parchment-lined baking sheet. Brush lightly with melted butte or aioli and toast for 5 minutes until just golden.12 slider buns
Assemble the Sliders
- Spread a generous layer of garlic aioli over the toasted bottom buns. Pile the roast beef evenly over the buns — 2–3 layers deep for hearty sliders.¼ cup homemade garlic aioli or mayonnaise, ½ pound deli roast beef
- Lay down your slices of cheese, then sprinkle the shredded mozzarella over the top for extra meltiness.12 slices melty cheese, ½ cup shredded mozzarella cheese
- Spoon an even layer of caramelized onions across the sliders.2 cups caramelized onions
- Place the top half of the rolls on the sliders. In a small bowl, mix together the melted butter, Worcestershire, poppy seeds, sesame seeds, garlic powder, dried minced onion, salt, and pepper. Generously brush the tops of the rolls with the garlic butter mixture.6 tablespoons unsalted butter, 1 teaspoon Worcestershire sauce, 1 tablespoon poppy seeds, 1 tablespoon white sesame seeds, ½ tablespoon garlic powder, ½ tablespoon dried minced onion, ½ teaspoon kosher salt and freshly cracked black pepper
- Cover loosely with foil and bake for 10 minutes. Remove the foil and bake for another 5–10 minutes, until the tops are golden brown and the cheese is nice and melty.
- Slice between the rolls to separate the sliders. Serve warm with little bowls of au jus on the side for dipping!
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