1 pound ground sirloin beef (90% lean)
Preheat oven to 375°F. Spray 13x9-inch baking dish with cooking spray.
Cook beef in large skillet over medium heat 7 minutes or until meat crumbles and is no longer pink; drain. Add drained tomatoes and 1 cup enchilada sauce; blend well.
Place tortillas in damp paper towels; microwave on HIGH 1 minute or just until flexible. Place about 1/3 cup beef mixture evenly on each tortilla. Top each with about 1 tablespoon cheese. Roll up and place seam side down in baking dish. Top with remaining sauce and remaining 1 cup cheese, spreading evenly and covering tortilla edges.
Bake covered 30 minutes. Serve with a dollop of sour cream, if desired.