Peel and chop onion and celery. Clean, wash and cut the leek into rings. Melt 1 tablespoon of clarified butter in a pot. Add onion, celery and leek and fry over medium heat for about 5 minutes while turning.
Deglaze with white wine and fish stock and bring to the boil. Wash the basil, shake dry, add to the fish stock with the star anise and simmer for about 30 minutes. In the meantime, wash the asparagus, cut off the woody lower ends.
Cut asparagus diagonally into pieces and cook in boiling salted water for about 5 minutes until al dente. Melt 3 tablespoons of clarified butter. Stir in flour and sweat briefly. Pour the sauce stock through a sieve and collect.
Pour into the roux while stirring, bring to the boil and simmer for approx. 2 minutes, stirring continuously. Season with salt and pepper and refine with vermouth and cream. Remove the asparagus, rinse in cold water and drain.
Heat 1 tablespoon of clarified butter in a frying pan. Fry the asparagus for 4-5 minutes. Prepare the pasta in a large pot with plenty of boiling salted water according to the instructions on the packet. Peel and slice garlic, wash shrimps and pat dry.
Wash 2-3 stems of thyme, dab dry, remove coarse stems. Remove the asparagus. Put the prawns into the hot pan and fry them for about 2 minutes while tossing. Add garlic and thyme and fry for about 1 minute more.
Remove thyme if necessary. Season shrimps with salt and pepper. Drain the noodles. Add the prawns, asparagus and sauce to the noodles, heat up briefly and stir-fry. Wash the remaining thyme, dab dry and remove small stalks.
Arrange noodles on plates, garnish with thyme.