Set the Instant pot on SAUTE & set it on NORMAL.
Add the ghee. When the ghee is moderately hot throw in the whole spices & allow them to sizzle until fragrant.
Next, shake off the excess marinated from the chicken pieces & add them to the pot. Fry the chicken pieces until lightly golden & no more water comes out from the meat. While frying the chicken it will release lots of water, that's normal. The frying process should take you about 5 mind.
Now,, in a bowl add the yogurt & the poppy seeds+cashew paste (see NOTES below how to make it). Whisk briskly to mix them into an uniform paste. Add this to the pot. Reduce the heat from NORMAL to LOW before adding this mixture. In high heat the yogurt might split.
Mix well with the chicken pieces. Keep stirring & up the heat back to NORMAL again in your Instant Pot. Keep stirring for 2-3 mins. The yogurt mixture will change color from white to slightly creamish & become intensely fragrant.
Add about 1/2-1 cups water. Mix well. Put the lid of the Instant Pot & seal the valve.
CANCEL the SAUTE mode & press the PRESSURE COOK button & set it on HIGH for 4 mins (see NOTES for more info on the cooking time). Pressure cook the rezala.
After 4 mins when the Instant Pot begins to beep do a Quick Pressure Release (QPR). Open the lid.
Throw in the rest of the special masala powder, the birista, the kewra water(if adding any) & the saffron soaked in water. Give everything a very good mix.
CANCEL the PRESSURE COOK mode & press the SAUTE button & set it on NORMAL. Simmer the Chicken Rezala for 2-3 mins. A beautiful layer of ghee will float on the top & your whole house will become fragrant.
Serve hot. Enjoy!