Onions peel and chop finely. Heat the fat. Fry the onions in it until transparent. Dust with flour and sauté. Deglaze with 2 litres of water and cream, bring to the boil, stir in stock and simmer for about 10 minutes.
Clean, wash and roughly chop the wild garlic and stir into the soup. Puree finely with a cutting stick. Heat the crab meat in the soup. Season to taste with salt, pepper and lemon juice. Arrange the soup and garnish with chervil
With 12 people: