1. Sauté onion and bell pepper in a lightly greased Dutch oven over medium-high heat 5 minutes or until tender. Stir in chicken and next 7 ingredients; remove from heat.
2. Tear tortillas into 1-inch pieces; layer half of tortilla pieces in 12 lightly greased (7-ounce) ramekins. Spoon 1/3 cup chicken mixture into each ramekin. Sprinkle ramekins with half of cheese. Repeat layers once. Place ramekins on baking sheets.
3. Bake at 350° for 18 to 20 minutes or until bubbly. Garnish, if desired.
Note: To make ahead, prepare recipe as directed through Step 2. Cover with aluminum foil, and freeze casseroles up to 1 month. Thaw in refrigerator overnight. Bake at 350° for 20 to 25 minutes or until bubbly.
To make casseroles in baking dishes, prepare recipe as directed through Step 1. Tear 6 tortillas as directed in Step 2. Layer one-third of tortilla pieces in a lightly greased 8-inch square baking dish. Top with 1 cup chicken mixture and 1/3 cup cheese. Repeat layers twice. Repeat procedure with remaining tortillas, chicken mixture, and cheese in another lightly greased 8-inch square baking dish. Bake at 350° for 50 minutes or until bubbly. Makes 12 servings. Prep: 20 min., Cook: 5 min., Bake: 50 min.