Ingredients

1 pound ripe tomatoes, quartered (about 5 plum or 3 medium tomatoes) 

Pinch of salt 

Pinch of sugar 

1 teaspoon freshly ground pepper 

1/2 teaspoon balsamic vinegar 

Preparation

In the bowl of a food processor fitted with the metal blade, puree tomatoes with the salt and sugar. Press through a fine sieve into a large bowl, and discard solids. Stir in pepper and vinegar, and transfer to a shallow metal baking pan.

Place pan, uncovered, in freezer; stir with a fork every 30 minutes until mixture is frozen, at least 2 to 3 hours.