Brown the chicken with the onion and peppers in a large skillet, stirring frequently; drain.
Stir in salsa, cream of mushroom, tomatoes and corn; bring to boil.
Place 6 tortillas, overlapping as necessary onto the bottom of a 13x9 baking dish. Spoon the chicken mixture over tortillas; top with 1 cup of the cheese. Top with the remaining 6 tortillas. Cover with foil.
BAKE 25 to 30 minutes or until heated through.
Remove from oven; uncover. Sprinkle with the remaining cheese.
Turn off the oven and replace the dish untils the cheese is melted.
Serve hot with a salad, chips or cold fruit on the side. Don't forget the sour cream!
Note: Sometimes Mom would add spices or salsa to the cheese topping. Or Ortega chiles. I loved it when she added some salt & pepper with garlic and the the Ortegas. This is still one of my favorite meals. :D. Especially when we had a fruit salad on the side.