Heat oil in frying pan, add the onion and fry, stirring for 5 mins.

Stir in the garlic and chorizo and cook for 2 mins. Mix in the paprika, thyme, stock and tomato puree and bring to the boil, stirring, add a little salt and pepper.

Add the sweet potatos and chickpeas to the slow cooker pot and pour over the hot stock mixture. Cover with lid and cook on low for 6-8 hours.

Serve.