Preheat oven to 350F.
Cook turkey and onion in a nonstick skillet over medium heat until browned, stirring to crumble. Remove from heat; add cumin and next 5 ingredients. Stir well and set aside.
Arrange half of green chilies in an 11 X 7 inch baking dish; top with 1/2 cup cheese. Spoon mounds of turkey mixture onto cheese, spread gently, leaving a 1/4 inch border around edge of dish. Top with corn. Arrange remaining green chilies over corn, top with 1/2 cup cheese.
Combine flour and salt in a bowl, gradually add milk, hot sauce, eggs, and egg whites, stirring with a whisk until blended. Pour over casserole. Bake at 350F for 1 hour and 5 minutes or until set; let stand for 5 minutes. Garnish with cilantro, if desired.
Yield: 6 servings.