Cut your strawberries into smaller pieces. Put into a bowl and combine with the sugar and the vodka (if you're using that) and stir until the sugar begins to dissolve. Cover the bowl with plastic wrap and set aside for at least two hours. Come back to stir it in between.
Place the strawberry mix into the bowl of your blender. Add the yogurt and the lemon juice to it and turn the machine until you have a smooth mixture. If you don't like seeds you can put it through a strainer to get rid of them.
Chil the mixture for at least an hour and than transfer to your ice cream maker following the instructions of the manufacturer.