1 (28 ounce) can refried beans
1 medium onion, diced
2 (10 ounce) cans black beans, rinsed
1 medium tomato, diced
1 teaspoon milk
1 cup nacho cheese sauce
1 cup shredded Cheddar cheese
2 limes, juiced
1/2 cup salsa
In medium broth or water, combine refried beans, onion, beans, tomatoes, milk, nacho cheese sauce, cheese, and Cheddar cheese. Mix thoroughly.
Transfer to a large baking dish. Top with Cheddar cheese and lettuce, then top with salsa. Chill 8 hours or overnight.