How to make
Beat the yolks with 4 tablespoons of sugar, add the finely grated rind of half a lemon, the juice of 2 lemons and continue to beat. Whip the egg whites into hard snow.
Dissolve the gelatin in half a cup of cold water, then pour it in 2 cups of boiling water, add it to the yolk foam, while stirring continuously, and then add the beaten egg whites.
Stir gently and pour this into cups. Serve with whipped cream and sprinkled with crushed biscotti.