In a large skillet, melt the butter over medium heat. Add the chorizo and cook until browned, about 5 minutes. Add the onion and garlic and cook until softened, about 5 minutes.
Stir the eggs into the chorizo and scramble until set, about 5 minutes. Spoon the egg mixture onto the lower third of each tortilla, leaving a 1-inch border on the bottom and sides. Top each with the cheese and cilantro. Roll up the tortillas burrito-style and serve with the toppings.