Puree the strawberry. Add sour cream, sugar and vanilla extract to the blender and blend well
Cover and freeze for atleast 4 hours. Then take it out and blend the mixture again until soft. Freeze again for 2 hours. Then break the crystals and blend it again until soft. More beating results in a creamy yogurt
Finally freeze it for atleast 6 hours. Before consuming keep the yogurt in room temperature for 2-3 minutes. Scoop the yogurt and garnish with chopped nuts;enjoy