Rejbak, kugel or potato cake? What you call it is up to you, it is important that it is tasty and with sausage!
Dice the sausage. Chop the onion. Use a hot frying pan to fry the sausage and onion until lightly golden.
Peel the potatoes and grate them on a fine grater. Press the resulting mass on a strainer so that it loses excess water. Mix the potatoes with the fried onion and sausage. Add marjoram, chopped parsley, salt, and pepper. Finally, add the egg and breadcrumbs for a non-runny consistency. If the mass is too runny, add more breadcrumbs.
Grease the baking tray with fat and sprinkle with breadcrumbs. Layer the potato mass and knead lightly. Bake the cake for 1.5 hours in 180 °C (356 °F).