Cut the rolls into cubes, pour warm milk over them. Steam the butter with the chopped onion and parsley, add to the rolls; Season with salt and pepper, add the cream. Put the filling in the duck and sew it up.
Place the duck in a greased baking dish, add the whole onion and pour hot fat over it.
Fry in a preheated oven (fan oven) at approx. 160-170 ° C for about 90-120 minutes.
In between, pour the frying fat over frequently, pour in approx. 3/8 l (= 375 ml) of liquid (water or stock) from the side.
When the back is brown, turn the duck over and brown the breast, watering it more often.
Brush with ice cold beer or salt water for the last 10 minutes at 240 ° C.