Try this, fry hamburger in pan then instead of brown gravy, put in tomato sauce. You could also use either frozen or canned vegetables. Mix all this together and bring to a slight simmer then put in your casarole dish. Prepare mashed potatos like you normally would with milk and butter in them then put it on top of your meat mix. Then add shreaded chedder cheese on top and bake it a t 350 till the cheese is melted.