Place 2 c chopped fresh strawberries in tupperware. Sprinkle 2/3 c sugar. Wait 15 minutes. Drain juice into saucepan. To pan add 1 envelope unflavored gelatin. Wait 2 minutes. Heat pan, stirring frequently, until gelatin dissolves and mixture smoothes. Pour over strawberries. Add 8 ounce strawberry yogurt, 1/2 c buttermilk, 2 T lemon juice. Mix well, then freeze 2 hours. Blend until smooth. Freeze 6 hours. Remove from freezer 15-20 minutes before serving.