In a large skillet over medium-high heat, sauté bell pepper and onion until tender (about 5 minutes).
In a large bowl, stir together chicken, condensed soups, tomatoes and chilies, and sautéed bell pepper and onion.
Arrange half of the tortillas in an even layer in the bottom of the prepared baking dish. I like to cut the tortillas in half so that it’s easier to cover the dish. It’s fine if they overlap some, too.
Spread half of the chicken mixture over the tortillas. Sprinkle with half of the cheese.
Repeat layers with remaining ingredients, finishing with cheese on top.
Bake, uncovered, for 25-30 minutes (or until heated through and bubbly).
Make Ahead: Assemble the casserole, wrap tightly, and store in the refrigerator for up to 1 day before baking. When ready to bake, allow the dish to sit on the counter and come to room temperature for at least 30 minutes before putting it in the oven.To Freeze: Before baking, wrap tightly in plastic wrap, cover with foil, and freeze for up to 3 months. When ready to enjoy, thaw in the refrigerator overnight, allow the dish to come to room temperature on the counter for 30 minutes, and then bake according to recipe instructions.To Bake from Frozen: Cover the frozen dish with foil for the first 30 minutes, and then continue baking the casserole for about 15-30 more minutes (uncovered), or until heated through.