Preheat your oven to 400℉ (200℃/Gas Mark 6).
Cut the larger potatoes ones in half to ensure even cooking. Arrange the potatoes in a single layer on a foil-lined baking sheet. Drizzle with a quarter cup of the olive oil and season generously with salt and pepper.
2½ lbs fingerling potatoes, 2 teaspoon kosher salt, 2 teaspoon black pepper, ½ cup olive oil
Place the garlic cloves in foil and pour in a tablespoon of olive oil with a hearty pinch of salt. Then wrap the garlic up tightly to form a small pouch. Place this on the baking sheet alongside the potatoes.
⅓ cup garlic cloves, ½ cup olive oil
Roast the potatoes and garlic in the preheated oven for 30-40 minutes, or until the potatoes are fork tender. Once done, remove them from the oven.
Gently smash the roasted potatoes using the flat bottom of a glass or a measuring cup. For the most crispy bits, use a fork to raise up some ragged pieces from the potato.
Create the garlic butter: Take the roasted garlic cloves and mix them with melted butter, the rest of the olive oil, salt, pepper, and fresh thyme leaves. Smash the garlic with a spoon to really release their flavor into the butter mixture.
2 tablespoon salted butter, 1 teaspoon fresh thyme leaves
Generously brush the smashed potatoes with the garlic butter mixture using a silicone brush or spoon. Return them to the oven and broil on low for 5-10 minutes, or until they are crispy and golden.
Serve the fingerling smashed potatoes hot, ideally as a side dish or as a party appetizer.