Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13 inch baking pan. Layer tortillas in bottom of pan so that edges overlap.
In a large bowl, beat together eggs and milk. Stir in cheeses, red pepper and green chiles. Pour egg mixture over tortillas.
Bake in preheated oven until eggs are set, about 25 to 35 minutes. Meanwhile, heat oil in a skillet or frying pan over medium heat. Add mushrooms and green pepper; saute until tender. Stir in enchilada sauce and heat until warmed through. Spoon enchilada sauce over baked eggs and serve.