Mix the fennel with the butter, salt and pepper, spread onto a baking tray lined with baking paper.
for approx. 30 mins. in the centre of an oven preheated to 220°C. Turn the fennel occasionally so that it browns evenly. Turn oven down to 180°C.
Place the fish fillets on the fennel, coat with butter, season. Distribute herbs and lemon on the fish.
in the centre of a preheated oven for approx. 12 mins.