10 (6- to 7-inch) corn tortillas, softened either in oil or in microwave under damp paper towel
4-5 cups enchilada sauce or leftover mole
3 tablespoons vegetable oil
2 boneless skinless chicken breasts, chopped or shredded (optional)
1 cup Mexican blend cheese, grated
1/2 cup onion, finely chopped
2-3 serrano chiles, seeded, deveined, and finely chopped
sour cream
Heat oil in skillet. Sautée onions and chiles till just tender. Add chicken if using and cook till just golden. Remove skillet from heat; combine contents with enough cheese to make 3 cups.
To make enchiladas: Place one tortilla on work surface. Top with 2-3 tablespoons filling. Roll close; secure with one or two toothpicks if necessary. Repeat with remaining tortillas.
Pour half the sauce into a 8x13x2 inch casserole dish. Arrange enchiladas over sauce. Top with remaining sauce.
Bake at 350° 20 minutes. Serve with sour cream.