lentil and tomato soup with cumin and coriander

2 tbsp oilve oil
1 medium onion, finely chopped
3/4 tsp ground coriander
3/4 tsp ground turmeric
3/4 tsp ground cumin
pinch of ground cloves
350g red lentils, washed
1.2 litres vegetable stock
400g tinned chopped tomatoes
20g fresh coriander leaves
salt and freshly ground black pepper

garnish:
1 tbsp olive oil
1 large fresh green chilli, chopped
2 tbsp coriander leaves

cook onion in oil for 5 mins in covered saucepan. Add dried spices, cook for 5 mins while stirring. Add lentils and stock, cover and simmer gently for about 20 mins till lentils are tender. Add tomatoes and simmer for 10 mins. Cool a little, then purée with coriander leaves. Taste for seasoning.