Required: One hard-boiled egg.

Half a pint of milk and fish stock. One ounce of butter. Three-quarters of an ounce of flour. Salt and pepper.

Melt the butter and stir in the flour smoothly over the fire for a minute or two. This gives the sauce a pretty, glazed appearance, but be careful not to allow it to colour. Next add the milk and some of the stock in which the fish was boiled. Stir over the fire until the sauce boils and thickens; then add the chopped boiled egg with salt and pepper to taste.