Peel the asparagus, cut off the woody ends. Wash asparagus shells and put them in 800 ml boiling water. Season with salt, sugar and lemon slice. Let it simmer at medium heat for about 20 minutes. In the meantime, cut the asparagus into very fine pieces. Clean and wash the sugar snap peas, also cut very finely.
Pour the asparagus peelings through a sieve, collect the stock, bring to the boil again. Cook the asparagus in this stock for about 5 minutes. Cook the sugar snaps for the last 2 minutes, pour through a sieve, collecting the vegetable water. Heat the fat in a saucepan and sauté the flour in it. Add the vegetable water while stirring constantly, bring to the boil. Season to taste with salt, pepper and vermouth. Whisk cream and egg yolk, stir into the soup. (Do not let it boil anymore!) Add vegetables. Remove shrimp shells, except for the tail piece, and intestines. Heat oil. Fry the prawns for about 3 minutes, turning them over. Season with salt, chilli powder and lemon juice.
Season to taste with salt, pepper and vermouth. Whisk cream and egg yolk, stir into the soup. (Do not let it boil anymore!) Add vegetables. Remove shrimp shells, except for the tail piece, and intestines. Heat oil. Fry the prawns for about 3 minutes, turning them over. Season with salt, chilli powder and lemon juice. Serve in the soup. Garnish with parsley