delicious and nutritious

Here is a recipe for a delicious and nutritious cheese sauce, useful for fish, savoury dishes, and various others. Make a roux with about an ounce or rather more of butter, and when this has melted, stir in a heaped dessertspoonful of flour. Stir till the mixture drops off the spoon, and then add half a pint of boiling milk. Continue to stir, and add a heaped-up tablespoonful of grated cheese. The yolk or an egg added is an improvement, but not a necessity. The sauce should be thick, creamy and served hot.