Sangrita

450g/1lb ripe tomatoes,or one 400g/14oz
can chopped tomatoes
1 small onion,finely chopped
2 small fresh green chillies,seeded and
chopped
120ml/4fl oz freshly squeezed orange juice
juice of 3 limes
2.5ml/1/2 tsp caster (superfine) sugar
pinch of salt
1 small shot glass gold or aged tequila
per person