Preheat oven to 400 degrees F (200 degrees C).

Coat chicken breasts with 1 tablespoon olive oil, salt, red pepper flakes, and garlic. Place in an 8x8-inch baking pan.

Bake in the preheated oven until chicken is no longer pink in the center and the juices run clear, 25 to 30 minutes. Chop chicken into cubes. Leave oven on.

Heat 1 tablespoon olive oil in a skillet over medium heat. Add bell pepper and onion and cook until tender, 4 to 5 minutes.

Mix onion mixture, cream of chicken soup, 1 cup cheese, 3/4 cup salsa, sour cream, and cumin together in a bowl. Mix in chicken and use some of the chicken drippings to moisten the mixture.

Layer chicken mixture and crushed tortilla chips until baking pan is full. Top with remaining cheese. Bake until golden brown and bubbly, about 30 minutes. Top with remaining salsa.