1Heat oven to 350°F. Spray 13x9-inch (3-quart) glass baking dish with cooking spray.
2In 12-inch nonstick skillet, cook beef, onion and garlic over medium-high heat 5 to 7 minutes, stirring occasionally, until beef is thoroughly cooked; drain. Stir in 1 can of enchilada sauce, the cumin and salt; set aside. In small bowl, mix egg, cottage cheese and chiles; set aside.
3Using remaining can of enchilada sauce, ladle 1/3 cup of the sauce into baking dish. Top with 4 noodles, half of the beef mixture (about 1 3/4 cups), half of the cottage cheese mixture (about 1 cup) and 1 cup of the shredded cheese. Repeat layers. Top with remaining 4 noodles. Pour remaining enchilada sauce over noodles. Spoon tomatoes over sauce.
4Cover; bake 45 minutes. Uncover; sprinkle with remaining 2 cups shredded cheese. Bake 10 to 15 minutes longer or until edges are bubbly. Let stand 10 minutes before cutting.