1Heat oven to 375ºF. Spray 13x9-inch (3-quart) glass baking dish with cooking spray. Tear 6 of the tortillas into bite-size pieces; spread in bottom of baking dish.
2Layer 1 can of the green chiles and half of the Monterey Jack cheese over tortillas. Sprinkle with jalapeño chili if desired. Repeat with remaining tortillas, green chiles and Monterey Jack cheese. Sprinkle with Cheddar cheese.
3In small bowl, beat eggs, egg whites, milk, salt and pepper until well blended; pour slowly over casserole.
4Bake uncovered 45 to 50 minutes or until set and golden brown. Serve with salsa.