Layer the following:

16 oz. refried beans
1 lb. cooked ground beef with 1 sm. chopped onion
1/2 lb. shredded cheddar cheese
1/2 lb. shredded Monterey Jack cheese
1 jar salsa, medium

Microwave for 15 to 20 minutes or bake at 350 degrees for 20 to 25 minutes.