Peel the celery and potatoes and cut into large cubes. Finely dice the onion.
Heat the rapeseed oil in a saucepan and sauté the above ingredients. Mix well. Now add milk and water and season with salt and pepper. Cook over medium heat for about 20 to 25 minutes.
Pluck the dill from the stalks and chop finely. Wash the shrimp under cold water and drain very well. Then season with the lemon juice and mix with the dill.
Mix the crème fraîche with the milk until smooth.
Puree the soup finely and season again with salt, pepper and lemon juice. Spread the crème frâiche and shrimp on the soup and garnish with chilli flakes and a little dill.
The soup is enough for two good eaters. As a starter it is certainly enough for 4 to 5 people.