For the sauce stock, peel and chop the onion. Clean or peel, wash and chop the leek and celery. Wash the basil. Heat 1 tablespoon butter in a pot. Sauté onion, leek and celery in it at medium heat for about 5 minutes.
Deglaze with wine and stock. Add anise and basil. Cover and simmer at low heat for about 30 minutes.
In the meantime defrost the frozen shrimps. Wash the asparagus, cut off the ends generously or peel the lower third. Cut the asparagus diagonally into pieces. Wash thyme, shake dry, chop.
Rinse shrimps and pat dry.
Pour the stock through a fine sieve and collect. Heat 2 tablespoons of butter. Stir in the flour and briefly sauté until light brown. Add the stock, Noilly Prat and cream while stirring, bring to the boil and simmer for about 5 minutes.
Season to taste with salt and pepper.
Meanwhile cook the pasta in 3-4 l boiling salted water (approx. 1 teaspoon salt per litre) according to package instructions.
Heat 1 tablespoon of butter in a large frying pan. Fry the asparagus for 4-5 minutes while turning. Season with salt and pepper. Take out, heat 1 tablespoon butter in the frying fat. Fry the prawns for 2-3 minutes, turning them over.
Fry the thyme briefly. Add asparagus and prawns to the sauce. Drain the noodles and mix with the sauce.