Peel and wash the potatoes and cook them in boiling salted water for about 20 minutes. Meanwhile cook brown lentils for about 30 minutes in boiling salted water. Add the red lentils 8 minutes before the end of the cooking time.
Wash and clean the soup vegetables and cut them into pieces. Cook in boiling salted water for about 10 minutes. Heat milk and fat. Drain potatoes, add milk. Mash potatoes with a potato masher.
Season to taste with salt and nutmeg. Drain soup greens and lentils. Layer potato puree, soup greens and lentils in a greased casserole dish. Whisk eggs, sour cream and cream cheese. Season with salt and pepper.
Pour over the casserole and sprinkle with cheese. Bake in the preheated oven (electric cooker: 200°C/ gas: level 3) for approx. 25 minutes. Wash the parsley and chop it and sprinkle it over the casserole except for something to garnish.
Serve garnished with parsley.