2 very large tomatoes, cut into quarters
1 small onion
3 tablespoons red wine vinegar
1½ teaspoon salt
pinch of cayenne pepper
Chop onion 5 seconds on speed 7.
Add tomatoes and chop 4 seconds on speed 5.
Add water and sugar and cook 13 minutes at 100C on speed 1.
Add vinegar, salt and cayenne. Blend for 30 seconds increasing speed slowly to 8.
Freeze overnight in ice cube trays. Next day before serving blend for 30 seconds on speed 9. If required, add water to facilitate blending.