In a large bowl combine crushed crackers, onions, eggs, ketchup, and celery mix gently do not over work. See the note on what happens if over worked. Slowly add milnot into mixture. Heat oven to 375 or on charbroil.
On a baking sheet form patties to the thickness you want bake or charbroil, this makes about 8 good sized patties, as they cook make sure the core temperature is 160 degrees.
You can add salt and pepper to taste, and melt cheese on top if cheeseburgers are desired. Choice of buns are left up to you. Cook until burgers are at desired consistence.