Cut the onion into fine cubes. Peel the apple, remove the core and grate coarsely. Sauté the onion cubes over medium heat in a little oil until at least translucent, if you like you can also fry them until golden brown.
Stay next to the pan, always stirring. Then add the grated apple, continue stirring until the liquid from the apple has evaporated and the fructose begins to caramelize. Then add the liver sausage and season to taste, marjoram definitely suits the dish. Do not salt, the sausage usually already brings enough salt.
The fat from the liverwurst will melt and give the meat ingredients a roasting base. Continue stir-frying until everything forms a homogeneous mass. Be sure to serve with sauerkraut, which is the appropriate counterpart to the sweetish fried liver sausage. Serve with potatoes, salted or with herbs, or mashed.