Grind the garlic and ginger with a splash of water in a wet grinder to a thick paste. In a large bowl add the garlic and ginger paste along with the turmeric powder and mix well. Add the chicken pieces to this paste and set aside to marinate for a few hours or overnight.
Grind all the ingredients for the pepper masala in a spice grinder and set aside.
Heat oil over a medium flame in a heavy bottom large sauce pan. Add the curry leaves and as they splutter add the onions. Fry the onions for 12 to 15 minutes stirring ever so often.
Now add the green chillies and fry for a minute. Add the tomatoes and fry for 8-10 minutes as they begin to soften stir well and mash lightly with the back of the spoon.
Add the marinated chicken and fry on a medium heat for 5 minutes. Stir well and add the pepper masala powder continuing to fry for 2-3 minutes as the chicken pieces seal.
Add water and scrape the bottom of the pan making sure it’s a thick paste coating the chicken. Season to taste and simmer over a low heat with the lid on for 25-30 minutes stirring half way through (add an extra 100 mls water if you would like a little more gravy). Take the lid off and stirring well, garnish with fresh coriander and serve with parathas or rice.
