PREPARATION:

1. Preheat oven to 400°F. Place tortillas on large baking sheet, overlapping as little as possible; bake 4 minutes. Turn tortillas; continue baking 2 minutes or until crisp. Cool completely on wire rack.
2. Heat medium nonstick skillet over medium heat. Add turkey and onion. Cook and stir 5 minutes or until turkey is browned and onion is tender. Add taco sauce, chilies and corn. Reduce heat and simmer 5 minutes.
3. Break 3 tortillas and arrange over bottom of 1-1/2-quart casserole. Spoon half of turkey mixture over tortillas; sprinkle with half of cheese. Repeat layers. Bake 10 minutes or until cheese is melted and casserole is heated through. Break remaining 3 tortillas into pieces and sprinkle over casserole. Garnish with sour cream.