Pre-cooked chicken is used extensively. The following recipe gives the ingredients and method to produce your own.
Ingredients:

2 kg chicken / cut into 1 inch cubes
1 cup vegetable oil
4 heaped tsp garlic & ginger paste
2 tsp salt
2 tsp curry powder
1 tsp turmeric powder
1 tsp coriander powder
1 tsp cumin powder
1 tsp Kashmiri chilli powder
1 tsp garam masala powder
4 heaped tbsp tomato puree
3 cups of water (or enough to cover the chicken)

Method:

1.      Add the oil to a pan and heat the oil
2.      Add the garlic/ginger paste and cook on a medium heat for about 2 minutes
3.      Add the salt, curry powder, turmeric powder, cumin powder, Kashmiri chilli powder and garam masala, stir in and cook for about 1 minute
4.      Add the tomato puree, stir in and turn the heat up high. Cook out for about 1 ½ minutes then add the water.
5.      Bring to the boil and then add the chicken and ensure the chicken is covered. If not add a little more water
6.      Turn the heat down to medium and cook the chicken for about 20 minutes with the lid on the pan until the juices run clear.
7.      Turn the heat down low and once the oil floats then the chicken is ready

The chicken can remain in the liquid to use or refridgerated