Wash and drain the chicken pieces.
Add chilli powder, coriander powder, turmeric powder, and pepper powder.
Mix well and keep the chicken to marinate for 15 minutes.
Heat two tablespoon oil in the pressure cooker.
Add half of the sliced onions, stir well, and cook on a low flame.
Once the onions are cooked to tender, add half of the chopped ginger and garlic.
Mix well and cook till the onions start turning brown.
Add the chopped tomato and green chillies, mix well and cook for a few more minutes.
Cook till the tomatoes become soft. Add chilli powder, coriander powder, garam masala salt and mix well.
Cook till you get a nice smell of the masalas.
Add the chicken pieces and curry leaves. Mix well to get a uniform coating of the masala.
Close the lid and pressure cook on high flame. After the first whistle, reduce to low flame and cook till the next whistle.
Switch off and let it cool.
In a cast iron pan (or any deep pan), heat some oil and shallow fry the remaining onions on a low flame.
When they are tender add the remaining ginger and garlic and continue frying until the onions start turning brown.
Open the pressure cooker (the pressure should be reduced and safe to open) and empty the chicken and masala to the pan.
Reduce on a high flame till the curry base starts to thicken while stirring continuously.
Add the coconut chips and curry leaves, mix well and cook on a low flame.
Switch off. Let the chicken ularthiyathu sit for a couple of hours before serving.