- Combine berries, sugar and lemon juice in a food processor; process until smooth.
- Add yogurt and pulse until mixed in. If using fresh berries, transfer the mixture to a medium bowl, cover and refrigerate until chilled, about 1 hour.
- Transfer the berry mixture to an ice cream maker and freeze according to manufacturer's directions. (Alternatively, freeze the mixture in a shallow metal pan until solid, about 6 hours.
- Break into chunks and process in a food processor until smooth and creamy.)
- Serve immediately or transfer to a storage container and let harden in the freezer for 1 to 1 1/2 hours.
- Serve in chilled dishes, topped with fresh berries.