Peel and finely chop one onion. Knead minced meat and diced onion. Season with salt and pepper. Form small balls from it. Fry the meatballs in hot clarified butter for about 10 minutes at medium heat.
Dice the pumpkin flesh. Clean, wash and cut the zucchini into pieces. Peel the rest of the onion and cut into slices. Remove meatballs from the pan. Fry pumpkin, zucchini and onion briefly in frying fat.
Pour in broth. Cook vegetables for about 10 minutes. Stir in sauce thickener and bring to the boil briefly. Stir in sour cream, add meatballs. Do not let it boil any more! Season with salt and coloured pepper. Pluck the marjoram leaves from the stalks and sprinkle them over the meatballs.