Chocolate Soufflé

2 ozs. butter
2 ozs. fine flour
¹⁄₂ pint milk
1 oz. sugar
2 ozs. powdered chocolate
4 eggs
¹⁄₂ tea-spoon vanilla

Melt the butter in a saucepan. Add the flour. Mix until quite smooth. Add the boiling milk gradually and stir together into a smooth paste. Strain through a sieve into a basin. Add the vanilla, sugar and chocolate. Add the well-beaten yolks when the mixture is nearly cold, and then the whites beaten to a stiff froth. Mix thoroughly and pour into a buttered mould. Steam for about an hour and a half.