Clean and wash the broccoli and cut it into small florets. Peel the carrots, wash them and possibly cut them in half lengthwise. Just before serving, cook the carrots in boiling salted water for about 10 minutes, broccoli for about 5 minutes. Then drain and toss briefly in hot fat. Wash the fish chops and pat dry. Fry in hot oil on each side for 3-5 minutes. Season with salt, pepper and a few drops of lemon juice.
Warm the mustard-cream sauce in a small pot while stirring. Meanwhile bring 300 ml water and milk to the boil for the puree. Remove the pot from the heat and stir in the potato powder. Season with salt and nutmeg. Pour the puree into a piping bag with star-shaped spout and squirt onto plates. Arrange steak, vegetables and mustard-cream sauce next to it. Serve garnished with mint