Keep frozen raspberries on hand in the freezer year-round so that, at a moment's notice, you can make this luxurious but simple dessert.
Puree raspberries with lemon juice in a food processor. To remove seeds, force the puree through a fine strainer into a bowl. Whisk in sugar and yogurt. If necessary, chill until cold.
Pour into the canister of an ice cream maker and freeze according to the manufacturer's instructions. (Alternatively, freeze the mixture in a shallow metal cake pan until solid, about 6 hours. Break into chunks and process in a food processor.)
1 fruit, 2 other carbohydrate