Clean and wash the leek and cut into fine rings. Peel, wash and thinly slice the carrots. Clean, wash and slice the mushrooms
Heat 1 tablespoon of oil in a large frying pan. Brown the mushrooms in it while turning them. Season with salt and pepper,
take out. Heat 1 tbsp. oil in the frying fat. Steam leek and carrots in it in portions. Add a good 1/4 l water and stock. Bring to the boil, cover and steam for about 10 minutes. Season to taste with salt and pepper
Wash the fish, dab dry, cut into 4 pieces if necessary. Sprinkle with lemon juice. Take off approx. 5 tablespoons of leek and mix with the mushrooms
Pour the leek and carrot mixture together with the stock into a large casserole dish. Salt the fish and place on top. Spread the leek and mushroom mixture on the fish as a topping. Sprinkle with seeds. Spread the fat in flakes on the fish.
Bake in the preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for 15-20 minutes. Cover after approx. 10 minutes if necessary. Wash the dill and cut finely except for a little garnish. Sprinkle fish with dill. Garnish with lemon and dill flags