Peel 2 onions, dice finely. Heat 1 tablespoon of oil in a saucepan, fry half of the onion in it. Add sauerkraut, season with salt and pepper. Pour in broth. Stew covered cabbage for about 20 minutes. Peel, wash and chop the potatoes. Cook in boiling salted water for about 20 minutes. Clean or peel and wash the soup greens and cut everything into small cubes. Peel garlic and cut into small cubes. Heat 2 tablespoons of oil in a pan and fry the minced meat until crumbly. Add soup greens, garlic and remaining onion cubes and fry for a few minutes, season with salt and pepper
Drain the potatoes and let them evaporate briefly. Add butter and milk, mash everything to a puree. Season to taste with salt and nutmeg. Pour 100 g cream into the sauerkraut, season to taste with paprika, salt and pepper. Put the minced meat in a high casserole dish. Spread the sauerkraut mixture over it. Finish with mashed potatoes. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for about 20 minutes. Whisk egg yolk and 2 tbsp. cream. Spread the puree with it. Bake for another 20-25 minutes until golden brown
Peel 1 onion and cut into thin rings. Turn the rings in flour and tap them off. Heat 1 tablespoon of oil and fry the rings in it until golden brown. Drain on kitchen paper. Sprinkle Shepherd's Pie with the onion rings and serve immediately