In a large skillet, cook beef and onion over medium heat until the meat is no longer pink; drain well. Stir in tomatoes, enchilada sauce, cumin, salt and pepper. Bring to a boil. Reduce heat; cover and simmer for 5 minutes. Pour half into a greased 13 by 9 by 2-inch baking dish; set aside.
Stack the tortillas and wrap in foil; warm at 350 degrees for 8-10 minutes. Spread warm tortillas with cream cheese and top with chilies; fold in half.
Arrange folded tortillas over meat sauce; pour remaining sauce over top. Cover and bake at 350 degrees for 15 minutes. Uncover; sprinkle with cheese. Bake 5 minutes longer or until cheese is melted.