Clean the fish fillets, remove the bones, place them in a greased flat baking dish and dust with salt, pepper and a little flour. Spread the potato slices on top like scales. Whisk the sour cream, pour over it and sprinkle everything with breadcrumbs and grated cheese. Put flakes of butter on top and bake at 225 ° for a good hour.
Goes well with green salad or raw vegetable salad.