Use two skillets: one to prepare the mixture and the other to heat the tortilla.
To heat the tortilla:
Lightly oil the skillet and heat on medium. Add the tortilla and heat on 2 sides. You may need to add a little more oil as you heat the tortilla, especially if you are cooking more than one. Keep warm while the mixture cooks. When the tortilla is heated, the pan is used to cook the egg.
To cook the egg:
Place the heated tortilla on a plate. Top with the bean mixture and then the egg with the cheese side up.
Makes one serving.