1

Put the frozen raspberries, yogurt, artificial sweetener and a pinch of dried mint into a food processor, and pulse until combined.

2

Tip the mixture into a freezer-proof container and fold in 150g fresh raspberries. Cover and freeze for 1 hour, then remove from the freezer, break up with a fork and stir well. Return to the freezer and repeat the freezing and stirring process twice more, then leave to freeze until firm.

3

If the yogurt becomes too solid, leave out of the freezer for 5-10 minutes to soften before scooping.