Make the Blue Corn Tortilla Dough
In a large mixing bowl, whisk together the kosher salt and masa harina to evenly disperse the salt through the flour.
Add half a cup of water to the flour and knead with your hands to start hydrating the dough. Add another half cup of water to the mix and knead with your hands, get it incorporated, then add the rest of the water.
Knead until the dough is soft, smooth, and no longer sticky. It should feel like play-dough.
Cover the bowl with plastic wrap and let the corn tortilla dough rest for 15 to 30 minutes before continuing.
Cook the Blue Corn Tortillas
Preheat a cast iron skillet over medium-high heat
Pinch off equal size pieces of dough and roll each one into a ball (we found them to be 85g or 1.80 oz on the kitchen scale for a good size taco. For smaller street tacos, try 70g.) Place the dough balls onto a plate and cover the dough with a wet paper towel as you finish creating more of them.
Wrap the tortilla press with plastic wrap on each side, then place a dough ball in the center of the bottom press. Press the tortilla until it's about ⅛ inch thick. It should not stick to the plastic wrap, crack, or break when you gently pull it up.
Place the pressed tortilla onto the hot skillet and cook on each side for 45 seconds to 1 minute. If it puffs up, don't panic that's a good thing!
Place the cooked corn tortillas on a plate, then cover with a damp paper towel to steam them and keep them nice and pliable.