How to Make It
In a wide, shallow dish, toss the raspberries, tomatoes, sugar and mint and let stand at room temperature for 10 minutes, until the raspberries and tomatoes release their juices. Stir well. Smooth the mixture to an even layer, cover and freeze for about 1 hour, stirring a few times, until just frozen. Using a fork or spoon, break up the granita, scoop it into bowls and serve.