I found this recipe for lemon ice cream in a book called "The Outlaw Cook", by John Thorne. The clever thing about it is that you don't need to make a custard first, and you certainly don't need an ice cream maker. I'm not sure it will come out smooth enough, but let's try it out.

Lemon Ice Cream

1 cup of superfine (caster) sugar
2 cups of cream
Juice of 1 lemon and its zest.