Wash the lettuce leaves and pat them dry. Clean the tomatoes and cut them into slices. Cut the pickles lengthwise into slices.
In a bowl combine the ground beef, egg, oats, onion, salt and pepper. Moisten your fingers and shape the mixture into flat patties.Heat 1 tablespoon oil in a sauté pan and brown the patty about 3 minutes per side over medium heat.
Season the pork schnitzel with salt and pepper. Heat the remaining oil in a pan. Over medium heat brown the Schnitzel for about 3 minutes per side.
Brown the liver loaf for about 2 minutes.
Slice the three buns open. Arrange the lettuce and pickles on the bottom halves of each.
Place the slice of liver loaf on one, the pork schnitzel on the second, and the beef patty on the third bun.
Add tomato slices to all three burgers and sprinkle with sunflower seeds. Dress with ketchup and finish the burgers with the tops of the buns.