Preheat oven to 375 degrees F (190C).
Spray a 13 x 9-inch baking dish with cooking spray and set aside.
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).