1. Cut up the skinless pike-perch fillet to obtain 2 thick pieces per serving (150 g / 5 oz. per person). 
2. In a saucepan, combine the white wine, shallots, salt and pepper in a saucepan and reduce by half. Add the cream and fish stock. Pour this mixture over the fish in a large skillet. 
3. Poach the fillets gently for 1 minute. Gently remove the juice and reduce by half. 
4. Sprinkle the pike-perch with the ground walnuts; cover and set aside. 
5. In a covered pan with a little water, cook the leek white, sliced into thin julienne. 
6. Cook the carrots and potatoes in boiling water. 
7. Arrange some leek whites on each plate; place 2 pieces of pike-perch on top.
8. Add the carrots and potatoes and surround everything with a ribbon of sauce and sprinkle with chervil.

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A recipe from Philippe Perrichon of the Restaurant Le Saint Jean in St-Amand