Mix together the natural yoghurt and the crème fraiche.
Stir into the lemon curd.
Churn in an ice-cream machine.
If you don't have an ice cream machine you can mix all the ingredients together in a large mixing bowl and then pour into a freezer proof dish. Put into the freezer for 3 hours or until the ice cream is solid.
Remove the ice cream 10 minutes before you need it so that it's easy to scoop.