Cut pike-perch and salmon into fillets of the same size.
Remove stems from chard, poach leaves briefly in hot water, rinse in iced water and spread out to drain.
Mousseline/Farce
Cut the fish into small pieces and mash with a hand mixer. Add a little grated lemon zest and the cream. Season vigorously with salt and freshly ground pepper. Important: All utensils must be iced.
Roll out puff pastry the size of the fillets and cover with chard leaves and place a fillet on top. Spread with the farce and top with the second fillet. Cover the whole with chard leaves and wrap with the pastry. Brush the seams with egg. Decorate the dough and brush with egg as desired. Put in the oven for 25 min. The first 10 min at 220 °C the remaining 15 min at 190 °C .
Sorrel sauce
Sauté shallots and sorrel leaves in butter until translucent. Add Noilly Prat and white wine, boil and extinguish with soup. reduce by half and add cream. Season to taste with salt and cayenne pepper.