Preheat oven to 350 degrees. Lightly spray 9x5-inch loaf pan with nonfat cooking spray. In medium bowl, combine ground meat, bread crumbs, onion flakes, tomato sauce, green chilis, egg and taco seasoning and mix until ingredients are blended. Divide mixture in half and place in prepared loaf pan; top with cheddar cheese. Press remaining meat mixture on top and spread smooth. Bake in preheated oven 45 min to an hour, until lightly browned and cooked through. Serve with sour cream and salsa, if desired.