Orange Mousse with Chocolate Wafers

• 2 oranges (1½ if very large)
• 4 eggs, preferably free-range
• 70 g caster sugar

Wash and dry the oranges; grate the rind on the finest part of a stainless steel grater. Put into a bowl with 2 eggs, 2 egg yolks (keep the whites) and the caster sugar. Whisk to a thick mousse, preferably with an electric mixer. Put 3 tablespoons of water in a little bowl, measure the gelatine care