Boil milk, and just before it starts to raise, turn down the heat, place in salmon and cod and simmer for 5 minutes.
Chop prawns, and after fish has been in milk for 5-10 min, break it into little pieces. Mix fish, prawns and potatoes together, adding salt and pepper (to your taste), and mayonnaise and/or sour cream.
Mix eggs together in flat bowl. In another bowl place flour, and in a third bowl breadcrumbs (I once didn`t have breadcrums and I crushed breakfast cornflakes- was even better!!!! Since then I haven`t used breadcrumbs).
Make patties from mixture- in size of flat tennis ball- cover in flour, then egg and then in breadcrumbs.
In large pan heat (about 2mm) oil and cook each cake till golden brown. As it will not be hot inside and to prevent from burning, put cooked fish cakes on an oven tray and place in oven (200 C) for 8-15 minutes or until they are piping hot inside.