Chop the onion.
Put the ground beef and pork in a bowl.
Add the chopped onion, breadcrumbs, milk, egg, salt, and pepper, then mix well.
Shape the mixture into round patties.
Heat oil in a pan and cook the Hamburg steaks over medium-low heat.
Flip and cook on the other side once browned.
Add steak sauce and simmer together.
Place the finished Hamburg steaks on a plate.