Heat the skillet. Place a nonstick skillet (or well-seasoned cast iron) over medium to medium-low heat. Add a tiny bit of butter/oil if your pan needs it.
Make the frico. Sprinkle about 1/4 cup shredded cheese into a circle slightly larger than your tortilla.
Add the egg. Crack 1 egg directly over the cheese. Season with a pinch of salt and pepper.
Smash the tortilla. Immediately place a tortilla on top of the egg. Press down firmly with a spatula so the tortilla bonds to the egg and cheese.
Cook. Cook 2 to 3 minutes until the cheese is deeply golden and crisp around the edges. Cover the pan for 30 to 60 seconds if needed to help the egg set.
Flip. Slide a wide spatula underneath and flip. Cook 30 to 60 seconds on the tortilla side to warm through.
Finish and fold. Transfer to a plate, add toppings (and optional protein), fold like a taco, and eat right away while crispy. Repeat with remaining tacos.
