For the gratinated plaice fillets, grease the gratin dish with butter and preheat the oven to 170 °C.
Pour the white wine into a saucepan and bring to the boil for approx. 2 min. Remove from heat and let it cool down a bit.
Add the whipped cream with the remaining ingredients and whisk everything together well.
Place the fillets in the buttered dish and cover with the whipped cream topping.
The plaice fillets are ready when the glaze has turned a nice golden color.