Royal icing

• 1¾-1 lb (350–450 g) icing sugar
• 2 large egg whites

Using a nylon sieve, sift the icing sugar on to a square of greaseproof paper. Whisk the egg whites and cream of tartar or lemon juice in a mixing bowl until frothy but not stiff. Using a wooden spoon, beat in half the sifted icing sugar, one-third at a time. Then beat very thoroughly for 10 minutes, until the mixture becomes light and fluffy and can be drawn up to a soft peak with the spoon.</