Peel and dice onions and fry in hot olive oil. Peel and dice the carrots and potatoes. Add both, fry briefly and add a liter of vegetable stock. Season with salt and a little pepper and cook for 20 minutes.
In the meantime, peel and dice the apples. Add after 20 minutes and cook for another 10 minutes. Add 4 tablespoon sour cream and season to taste again. Finally sprinkle with freshly chopped parsley and serve.