For the filling, clean, wash and chop the broccoli, cover and stew in 200 ml of boiling water for 12 minutes. Then puree with the cutting stick. Stir in egg, 1 teaspoon of cream, breadcrumbs, salt, pepper and a teaspoon of lemon juice.
In the meantime, wash and peel the potatoes and cook them for about 20 minutes. Clean and wash spring onions, cut into long strips and blanch in potato water for 1 minute. Take them out and quench. Cut the fillets lengthwise in the middle, spread the filling in and wrap leek strips around it, salt.
Heat lemon juice and 200 ml water in a frying pan, cover and cook the fish for about 10 minutes. Remove and keep warm. Stir in remaining cream, bring to the boil again and thicken with sauce thickener.
Meanwhile wash the dill, dab dry and cut finely. Drain the potatoes and sprinkle with dill. Serve on preheated plates with lemon wedges and dill garnish.