I want to make sorbet or ice cream

This rely's on catching it at the right consistency. After that it gets rock hard. But you can soften it.
http://food52.com/recipes/15836-strawberry-yogurt-ice-cream

It's hard to make ice cream or sorbet without an ice cream maker. What about making a granita? Here's a great recipe for a frozen yogurt and mint granita http://food52.com/recipes/3482-feta-frozen-yogurt-with-blood-orange-and-mint-granita