Heat the oil in a large frying pan or saucepan over a medium-low heat and fry the onion for 10-12 mins until softened and beginning to turn golden. Stir in the garlic and cook for 1 min, then add the squash and cook for a few minutes more to soften slightly. Scatter in the spices, stir to combine, and cook for 2 mins until fragrant.

Tip everything in the pan into the slow cooker along with the chickpeas and their liquid, the tomatoes, tomato purée and the stock. Mix well, then cook on high for 5 hrs or low for 7 hrs. Serve alongside couscous, with the coriander sprinkled over.