Preheat oven to 350°.
Coat bottom and sides of a 9-inch pieplate with cooking spray and line with tortillas. Set aside.
Cook meat, chiles, and onion in a large nonstick skillet over medium heat until meat is browned, stirring until it crumbles. Drain. Add cheese; stir well. Spoon meat mixture into prepared dish.
Combine egg substitute and remaining 4 ingredients in a large bowl; beat with a wire whisk until well blended. Pour egg mixture over beef mixture. Bake at 350° for 45 minutes or until set. Cut into wedges, and serve warm.