Wash the fish, dab dry and sprinkle with lemon juice. Clean and wash the zucchini and cut them into long, wide strips with a peeler. Peel and finely chop the onion. Fry briefly in hot oil.
Add fish and zucchini, season with salt and lemon pepper and deglaze with white wine. Steam covered at low heat for about 7 minutes. Lift out and arrange on a preheated plate.
Melt the fat in the fish and vegetable stock. In the meantime, mix sauce powder, 5 tablespoons of water and cream and bring to the boil while stirring in the stock. Season to taste with orange juice. Serve garnished with parsley and orange slice.
Boiled potatoes taste good with it.