In a large pan or casserole pot gently cook the onion for 5 minutes in the sunflower oil. Next add the garlic, ginger, garam masala and curry paste, continue cooking for 3 minutes over a medium heat.
Add the potatoes and chickpeas and stir them into the spices making sure everything is coated. Pour in the tinned tomatoes and coconut milk and bring to a steady simmer. At this stage add a little salt and milled pepper. Continue cooking until the potatoes are soft. If the sauce feels a little dry just add a little water.
Just before serving stir in the spinach and coriander and serve with yoghurt.