Clean the fish fillets and sprinkle with grated lemon zest.
Chop the herbs very finely. Sprinkle a teaspoon of the herb mixture on the fish fillets. Cover and chill for about half an hour.
Mix the rest of the herb mixture with Parmesan cheese, chopped white bread, breadcrumbs, cream, salt and pepper to a moist filling, leave to stand for a moment, then spread on the underside of two fillets, cover with the two remaining fillets and stick together with 2 roulade sticks each.
Flour the filled fillets. Melt the butter in a pan, fry the fish fillets for approx. 3 minutes on each side.