Tomato soup

INGREDIENTS

• 1-1.25kg/2lb 4oz-2lb 12oz ripe tomatoes
• 1 medium onion
• 1 small carrot
• 1 celery stick
• 2 tbsp olive oil
• 2 squirts of tomato purée (about 2 tsp)
• a good pinch of sugar
• 2 bay leaves
• 1.2 litres/ 2 pints hot vegetable stock (made with boiling water and 4 rounded tsp bouillon powder or 2 stock cubes)