Sweet potato chilli

Name: Sweet potato chilli recipe
Prep time: 10 mins
Cook time: 25 mins
Yield: Serves 4
Ingredients: 6 cloves garlic, peeled; 1tbsp vegetable oil; 1tsp cumin seeds; 3tbsp tomato puree, mixed with 125ml (4fl oz) water; 2 x 400g (13oz) cans chickpeas, drained and rinsed; 3 medium sized sweet potatoes, 2cm (¾in) diced; 3 green chillies, de-seeded and sliced; 1tsp ground cumin; 1tbsp lemon juice; Large pinch cayenne pepper; 400ml (13fl oz) vegetable stock or water; Coriander leaves, to garnish; Flat bread and raita, to serve