Heat oven to 350°F. In 10-inch nonstick skillet, cook ground beef and onion over medium-high heat until beef is thoroughly cooked, stirring frequently. Drain. Add corn; cook and stir about 3 minutes or until corn is thawed. Stir in sour cream, green chiles and 1 cup of the cheese.
Spread about 1/4 cup of the enchilada sauce in 13x9-inch (3-quart) glass baking dish. Spread about 2 teaspoons enchilada sauce on each tortilla. Top each with 2/3 cup beef mixture. Roll up tortillas; place seam side down over enchilada sauce in baking dish.
Drizzle remaining enchilada sauce evenly over filled tortillas. Sprinkle with remaining 1 cup cheese. Spray sheet of foil with cooking spray; place sprayed side down on baking dish and seal tightly.
Bake at 350°F. for 45 to 50 minutes or until thoroughly heated. Serve garnished with lettuce, tomato and additional sour cream.