Throw the crayfish in boiling water and cook them for 1 to 2 minutes. Take them out and refresh them in cold water. Peel and set aside.
Clean the celery, leeks and potato. Peel the potato, onions and garlic clove. Wash the tomatoes. Cut the vegetables into small pieces, except the potato.
Slightly crush the crayfish shells, brown them in a little hot butter and oil. Add the celery, leeks, onions, garlic, tomatoes, peppercorns, thyme, bay leaf, dill and parsley.
Moisten everything with the Noilly and the white wine, reduce quickly. Add enough fish stock to cover the shells. Grate the raw potato in this preparation and simmer for 1/2 hour.
Meanwhile, clean the spring onions, blanch them and slice them.
Clean the carrots, potatoes and celery and cut them into thin matchsticks.
Salt the zander fillets and sprinkle them with a little lemon juice.
Dab the vegetables with paper towel and pat them dry with a kitchen towel. Salt, pepper. Arrange the vegetables on the pike-perch fillets, packing them tightly together.
Brown the fillets on both sides in the butter.
Then pass the sauce through a sieve and finally beat it with a little cold butter. Mix the spring onions and crayfish with the sauce and serve with the pike-perch fillets.
Source:The New Kitchen
