In the bowl of a blender add the fish fillet, over the egg, onion, the bread, season with salt & black pepper to taste.
Form tubs, put them in a greased tray with butter & give in the oven overheated at 200 C for 8-10 minutes.
In the meantime we cook the sauce.
In a well-heated saucepan we melt our butter, add the flour we mix all 30-40 seconds, pour the water, mix until we have cocoons, add our cream, season with salt and black pepper to taste.
Mix and boil for 2-3 minutes.
We pour the sauce over the slopes, reduce the temperature to 180 C.