Soak rye grains in water for one night. Make together with the soaking water in a saucepan for one hour. Drain in a sieve. Steam dry.
Peel and dice onions. Heat butter in a frying pan. Fry the onion cubes in it until translucent. Mix with the rye in a baking bowl.
Stir eggs with whipped cream and cheese. Remove peel from potatoes and carrots.
Roughly grate into the egg-whipped cream mixture on a raw vegetable grater. Season generously with sea salt and freshly ground pepper.
Grease an ovenproof dish. Alternate layers of rye and potato-carrot mixture.
Bake in heated oven at 225 °C (gas stove: level 4/circulating air: 200 °C ) for approx. 45 minutes. Serve garnished with parsley.
Serve with green leaf salad in yogurt marinade with chopped walnuts.
Tip: The higher the fat content of the yogurt, the more aromatic and creamy the result!