Pike perch fillets wash and pat dry. In the juice tray of the oven, fill the butter, lemons and garlic slices with wine and water.
Put the pike-perch fillets on it and let them cook gently at 100 degrees convection for 15-20 minutes (depending on the thickness). In the meantime, prepare the sauce. To do this, wash the herbs, dab dry and chop.
Bring the fish stock to the boil with the white wine and remove from the heat. Mix egg yolk and cream and pour into the stock, stir. Return to the heat and boil down to the desired consistency, whisking constantly.
Add in the herbs and mustard, season with a squeeze of lemon juice and lemon pepper. If the sauce does not thicken nicely, thicken lightly with cornstarch. But not too thick, or the sauce will lose its foam.
Arrange the pike perch on a warmed plate, pour the sauce over it and enjoy.