1. Place all the vegetables and spices for the broth in a large pot. Add the 2.5 l of water and simmer for 20 minutes. Then add 2 dl dry white wine an 3 dl red wine vinegar.

2. Wash the crayfish by rinsing them quickly under cold water. Plunge five of the crayfish in the boiling broth and allow to cook for three minutes. Remove them from the broth and set aside. Repeat with the remaining five crayfish. Allow to cool and peel the crayfish.

3. In a sauté pan, place 50g butter, ½ a fennel, ½ an onion, and the 2 celery stalks, all thinly sliced. Add a large pinch of salt. Allow to soften over medium heat, making sure not to brown the vegetables. Add just enough of the broth to moisten the vegetables. Then add ¾ of the heavy cream (330g) and cook over low heat for 20 minutes. When ready, sift through a tamis by pressing the mixture through. Allow to cool before adding the rest of the double cream. If needed add more salt and pepper. Store in the fridge.

4. Chop the celery root into 3mm cubes.
Plunge in boiling salted water, and cook for 2 minutes. Drain and cool.

5. Toss the crayfish tails and claws in the truffle vinaigrette. Sprinkle the tails with ¾ of the chopped truffles. Keep cold. Season the celery root cubes with the truffle vinaigrette.

6. Glaze the center of the serving plates with the ice cream. Place the crayfish tails in the shape of a flower at the center, and the claws around it. Sprinkle with the celery cubes, chopped chives, chervil, and the remaining truffle.