Sprinkle sliced kiwi with 1 packet Sweet’N Low. Cover; chill overnight. In saucepan, melt margarine. Add leek, kiwi, potato, consommé, 1 packet Sweet ‘N Low and mint leaf; simmer 6-8 minutes. Adjust seasoning, if desired. In blender, puree mixture. Chill about 1 hour or until mixture coats a spoon thickly; add yogurt and puree again. Serve in chilled soup cups. Float reserved kiwi slices on top.