Heat the oil in a wok and fry the onion over a low heat until softened. Stir in the garlic, ginger and chillies how to cook chickpeas cook for a further 5 mins until the onions are golden and the garlic slightly toasted.
Add the turmeric, garam masala and cumin, stirring over a low heat for a few secs. Tip in the chopped tomatoes and add the tomato purée, then simmer for 5 mins. Simmer for 10 mins before stirring in the spinach to wilt. Season and serve with rice or naan.