To prepare the souffle: SEPARATE the yolks from the egg whites. Beat the egg yolks with 15 g sugar substitute powder and cook on a double broiler till light and fluffy. Soak gelatine in a little cold water and place on a double boiler. Cook till the mixture becomes clear and transparent. Heat the milk till lukewarm and slowly add to the egg-sugar mixture. Beat well. Add gelatine to the custard, beat well and place over crushed ice to set. Beat the egg whites till stiff. Add 3 g sugar substitute powder and beat well. When the custard is about to set, gently fold the beaten egg whites into the custard and place over crushed ice or keep in the refrigerator till set. To prepare the plum sauce: Peel and de-stone the plums. Chop them coarsely and puree them. Put the plum puree and five g sugar substitute powder in a heavy bottomed pan and cook on low heat till the sugar is dissolved and the mixture is thick. When cool, refrigerate till serving time. Beat the cream with 2 g sugar substitute powder till light. Keep aside. Put a little plum puree in each parfait glass, followed by a little beaten cream and a little plum puree. Pipe the remaining beaten cream over. Garnish with mint leaves and plum slices. Serve cold. NOTES : Souffle served with plum sauce and beaten cream