Tomato and basil soup

1 large onion, chopped
1-2 garlic cloves, crushed (optional)
1136ml/2pt stock made with Bovril or Vecon
908g/2lb tomatoes, skinned and chopped
bouquet garni (parsley, thyme and bay leaf)
chopped basil
fat free natural yogurt, to garnish
sprig of basil to garnish

1. Put the onion, garlic (if using), and 284ml/½pt of stock in a large heavy-based saucepan. Cover the pan and bring to the boil.

2. Continue boiling for 5-10 minutes, then uncover the pan, reduce the heat and simmer gently for about 20-30 minutes, until the onion is tender, golden and syrupy.

3. Add the tomatoes to the cooked onion in the pan. Cook gently for 3-4 minutes, then add the remaining 852ml/1½ pints of hot stock and the bouquet garni.

4. Simmer for 15-20 minutes, then remove the bouquet garni and puree the soup in a blender.

5. Tip the soup back into the pan, season to taste and add some chopped basil. Reheat before serving, garnished (if at home) with a swirl of natural yogurt and a sprig of basil.