Beat the egg whites until they're really stiff. Add the yoghurt and whip until it's combined. Pour the mix into a 500ml Sinchies pouch and begin piping your drops onto some baking paper than has been cut to size to fit your dehydrator. Dehydrate for about 8 hours or until they're nice and crispy.
I have heard that you can dehydrate these in a low temperature oven but i haven't tried it yet so can't say for sure if it will work.