In a large pot, melt butter, add salt, curry powder and pepper, then the flour. Cook for five minutes.
Add the milk slowly, keeping the mixture at a boil all the time.
Bone out the tin of salmon and then add to pot.
Stir carefully, so as not to break up the salmon too much.
Put a layer of sliced hard-boiled egg on the bottom of the baking dish and pour over the fish mixture.
Pipe mashed potato over the top and sprinkle with grated cheese.
Grill until the top is golden brown.
