Chickpeas with tomatoes & spinach

INGREDIENTS

• 1 tbsp vegetable oil
• 1 red onion , sliced
• 2 garlic cloves , chopped
• ½ finger length piece fresh root ginger , shredded
• 2 mild red chillies , thinly sliced
• ½ tsp turmeric
• ¾ tsp garam masala
• 1 tsp ground cumin
• 4 tomatoes , chopped
• 2 tsp tomato purée
• 400g can chickpeas , rinsed and drained
• 200g baby spinach leaves
• rice or naan bread , to serve