The egg, sliced onion, milk, and ketchup in the meat composition contribute to the meatloaf being juicy and flavorful. This traditional meatloaf recipe with panko bread crumbs normally calls for the entire milk, but any kind of milk, including dairy free milk replacements, can be used.
In other recipes, the onions are fried before being added to the uncooked meatloaf preparation. This guarantees the onions are cooked properly and tender. If the onions are sliced small enough, they will cook completely throughout the baking stage, so they do not require sautéing. By omitting the frying or sautéing stage, you may create the meatloaf easily and quickly.