Peel and finely chop the onions. Heat the fat and fry the onions in it. Add 1 1/2 litre water and soup paste. Bring to the boil while stirring.
Refine with crème fraîche. Season to taste with salt, pepper and sherry. Warm up the crab and mussel meat only briefly. Serve garnished with dill
Preparation time approx. 15-20 minutes