Defrost the prawns if necessary. Wash the fish, dab dry and cut into bite-sized pieces. Sprinkle with lemon juice. Peel onion and garlic and chop finely. Wash and clean the mangetouts and cut them diagonally in half.
Cook the pasta in 3-4 l boiling salted water (approx. 1 teaspoon salt per litre) according to the instructions on the packet. Cook the sugar snap peas for the last 2 minutes.
For the prawn sauce, rinse the prawns and pat them dry. Heat 1 tablespoon of oil in a saucepan. Fry the prawns, onion and garlic for 2-3 minutes while turning. Season with salt and pepper and remove.
Heat the butter in the frying fat. Sprinkle flour over it, sweat lightly while stirring. Deglaze with wine, 200 ml water and cream while stirring. Bring to the boil and simmer for about 5 minutes. Heat up the shrimps again briefly.
Season the sauce with salt and pepper.
In the meantime heat 2 tablespoons of oil in a frying pan. Dab the fish dry and fry it for about 3 minutes, turning it over. Season with salt and pepper.
Drain the noodles and sugar snap peas. Mix with the shrimp sauce and serve with the fish.