Banana and Grape Vacherin

• 3 egg whites
• 175 g/6 oz castor sugar
• about

Set the oven to very cool (120°C, 250°F, Gas Mark ½). Lightly oil sheets of greaseproof paper or foil large enough to cover two big baking trays. Dust with castor sugar.

In a large bowl whisk the egg whites until stiff and rather dry. Add half the castor sugar and beat again until the meringue mixture looks shiny, and is very stiff. Carefully fold in the remaining castor sugar with a la