I saw this recipe on the We Don't Have a Blog Blog, made by Coby. It's a Tessa Kiros recipe from 'Apples For Jam'. I've borrowed this book from the library before, and now I've ordered it from the Book Depository (early birthday present!)
You whisk together 250 ml single cream and 200 g caster sugar until the cream thickens a bit, then add 1 tsp vanilla extract and 500 ml buttermilk. Churn it up in an ice cream maker and put it in the freezer to harden.
It makes a tangy, fresh-tasting ice cream which is perfect with fruit. Everyone else had chocolate topping and hundreds-and-thousands with theirs though!