Scramble eggs in butter over low heat until soft and fluffy. Season with salt and pepper. Set aside.
Heat a clean nonstick skillet over medium heat. Add a thin, even layer of shredded cheese in a tortilla-sized circle.
Once cheese starts to melt, place a tortilla on top and press gently. Let cook 1–2 minutes until cheese is crispy underneath.
Flip the tortilla so cheese side faces up. Add scrambled eggs and any toppings to one half, then fold the taco closed.
Cook 1–2 more minutes to seal and warm through. Remove, slice, and serve. Repeat for remaining tacos.