Heat a griddle or cast-iron skillet over medium-high heat.
Place the tortilla beef-side down onto the hot surface.
Press firmly with a spatula for about 10 seconds.
Cook for 2–3 minutes until the beef develops a crust.
Flip so the tortilla side is down.
Immediately top with a slice of American cheese.
Cook another minute until the tortilla is golden and the cheese melts.