In a large wok heat up the oil on medium heat until hot
Add the chopped onions and the diced tomatoes then cook for 4-5 minutes until soft
Add the garlic paste, ginger paste, chopped green chilli, salt, chilli powder, garam masala and tomato puree then cook the spices for 3-4 minutes
Add the chicken and mix the spices to fully coat the chicken then cook for a further 10 minutes
Add the water and cook for a further 25-30 minutes until thickened to your personal preference – the oil will form a thin layer on top of the curry which will indicate that the curry is ready
Serve immediately and enjoy with chapati or garlic naan!