Boil jacket potatoes, cool, peel and slice. Fry the ham without oil until golden brown. Add melted butter and sliced potatoes, fry, add chopped onion and paprika powder, suate. Slice fish fillets and roll in the flour , heat 1 tablespoon of butter in a pan and fry floured fillets on each side until golden brown. Melt remaining butter in the another pan and add the flour, stirring occasionally, pour milk, add mustard, bring to a boil, add cream, salt and season to taste. Add fried fish and potato slices, serve.