Optional - To make garam masala, dry roast all the whole spices on a medium heat until aromatic and crunchy. Make a fine powder.
Add chicken to a large pot along with 2 tablespoons water. Add crushed onions, ginger garlic paste, garam masala, chili powder, salt, turmeric, ghee and lemon juice.
On a medium flame, cook the chicken till it is soft cooked and tender. Little water can be added while cooking if the chicken turns dry. Once done, turn off the heat. Excess moisture in the pot at this stage is alright.
If you want you may cool this and refrigerate immediately. Fry the chicken only when required, for up to 2 days.
Heat oil or ghee in a pan, add curry leaves and green chilies.
Fry till the leaves turn crisp and aromatic.
Add the cooked chicken along with the stock/ masala. Add the cashew powder and pepper powder.
Fry on a medium high flame till all the excess moisture is evaporated.
Keep stirring well and fry for 3 to 4 mins or till you get a nice aroma of cashews. The masala should coat the chicken well. If you want add little ghee at this stage.
Garnish chicken fry with fresh chopped coriander leaves. Sprinkle some lemon juice and serve hot with rice, rasam or any vegetable curry.