Peel and finely dice the onions and carrots. Sweat in hot fat. Deglaze with white wine, fish stock and 750 ml water. Cook soup for 10 minutes, pour through a sieve, bring to the boil again.
Add soup paste while stirring. Season with salt and pepper. Warm the crab meat only briefly in the soup. Serve in portions with 1 blob of crème fraîche and finely plucked dill