Whether you are trying to figure out something to do with all those leftover mashed potatoes, or you are ready to make a new fresh dish, these fish cakes are a fun spin on more traditional recipes. You can use premade mashed potatoes and precooked salmon to mix together, or you can make up some fresh mashed potatoes and combine with salmon trim. You will use one part potatoes to one part salmon and combine with an egg, tarragon herb salt and pepper. Form patties and then dip them one by one into a beaten egg and coat with breadcrumbs. Either fry in a bit of oil or bake until golden brown. Serve as burgers, on top of salads or simply with your favorite dipping sauce. You can also freeze them to enjoy later.