This is the meat loaf that my mom taught me to make. Your father loves it because it doesn't have a lot of strange "stuff" in it. It's really easy and you can do it ahead--Form it and refrigerate until ready to bake or bake ahead, cover, and reheat. Don't worry too much about amounts, this is easy to improvise with. If you don't have saltines, use bread crumbs or sliced bread mushed up with milk.
1 lb ground beef
1/2 a pack of saltines, broken up (I usually break them up in the package)
1/2 cup of milk
1/2 onion, chopped finely
1 clove garlic, finely minced
salt & pepper
1 can tomato sauce, to top
Mix everything, but tomato sauce together. It should be fairly soft, but still hold a shape. If it's not add some more milk or some of the tomato sauce. Form into an oval in greased baking dish.
Add some water to the pan and bake at 350 for 45-60 minutes.