What is the very best hamburger you could make? The recipe.?

My best hamburger would be 1/2 pd, hamburger, 1/2 pd ground pork, 1 egg, salt and pepper, finely diced onions and mushrooms, 1/2 tspn Italian seasoning, mix very well, make large patties, fry up, toward the end of cooking, place thinley sliced cheddar cheese on it, and melt, put on sourdough bread, toasted or not, with lettuce and tomatoes, with salsa, salad peppers on the side! mm, mm, good!