Red fish rosettes in cream and wine sauce

Give the fillets an unusual shape, and a simple dish will become beautiful and festive.

Ingredients:
Onions 2 pieces
Vegetable oil 1 tbsp + for greasing
Dry white wine 120 ml
Double cream 120 ml
Salt to taste
Ground black pepper to taste
Sugar ½ tsp.
Red fish fillet 350-400 g