Take all the ingredients mentioned under "For Masala"(in the ingredients list) in a blender and grind to a fine paste. You can add little water while grinding. Check notes for Substitutes.
In a wide pan, add cooking oil. Once hot, add mustard seeds.
As soon as mustard splutters, add curry leaves and chopped shallots(or Onions).
Once shallots turned soft, add turmeric powder, Red chilli Powder, coriander Powder and mix well. Let it cook for a mins.
Add ginger and garlic paste and mix well. Cook till raw smell goes off.
Now add cleaned chicken pieces and required salt. Cover and cook for 5 mins over medium heat. No need to add water.
Add the ground paste, 2 cups of water to the pan and bring it to boil.
cover the pan and turn the heat to low. Simmer for 15 - 20 minutes or until chicken is cooked through. Don't forget to stir now and then.
Add chopped coriander leaves/ Cilantro and Switch off the heat.
Serve Indian Chicken Curry with Rice or any flat breads.