Watercress, Spiced Tomato and Chick Pea Soup

Ingredients

• 1 tbsp vegetable oil
• 1 onion, chopped
• 2 cloves garlic, crushed
• ½-1tsp crushed flaked chilli
• 2 (397g) cans chopped tomatoes
• 1 (400g) can chick peas, drained then a few reserved for garnish
• 750ml/11/4pt vegetable stock
• 2 tbsp tomato puree
• 1 (100g) bag watercress
• A squeeze of lemon juice
• Salt and freshly ground black pepper