Make a biscuit base with digestives and butter......1 pack digestives and 1/4 cup melted butter. Press into the bottom of a small sandwich tin or loose-bottomed flan tin,and chill for 1 hour. Find a bowl with a circumference the same or a bit smaller as your tin. Line it with clingfilm, then fill with slightly softened icecream. Make sure you pack it in very tightly,then put in freezer until frozen.Loosen from the bowl and gently place over the biscuit base. Make the merangue with the whites of 4 eggs plus 1 tablespoon of sugar. Cover the icecream COMPLETELY with this-there must be NO gaps......bake in a pre-heated oven for aprox 6-8 min-the merangue should be just colouring a bit....it's done!! Good luck