Slices smeared with some of the butter. The fish is shredded and mixed with coarsely chopped mushrooms and onions. The mixture is seasoned to taste with salt, pepper and allspice and applied on toast. Top put a slice of cheese. The sandwich is placed in a greased pan with the remaining butter and bake in a hot oven for 5-6 minutes. Immediately after removing sprinkle with chopped parsley.