3
Add the onion, garlic and ginger to the pan and cook, stirring, for 2 minutes over a medium-high heat. If the paste is burning or sticking to the base of the pan, add a splash of water. Add the remaining salt and ground turmeric, followed by the ground coriander, ground cumin, chilli powder, tomato purée and diced tomatoes. Pour in 600ml warm water and cook for 5 minutes. Keeping the pan on a medium-high heat, let the liquid reduce for 15 minutes or until the oil comes to the surface and seeps to the sides of the pan