Add all the marinade ingredients to a large bowl and mix thoroughly with the chicken. Cover and leave to marinate for at least 1 hour (overnight would work even better).
When you are ready to begin, rinse the rice in a sieve until water comes out nearly clear (around 2 minutes). Set aside.
Set the instant pot to saute and add the coconut oil. Once melted add the onion and fry until softened (around 5 minutes). Add the garlic and fry for a further 1 minute.
Add all of the spices and fry for 1 more minute (the smell should be amazing!).
Add the marinated chicken and all of the marinade to the instant pot and saute for around 3 minutes.
Add all the remaining ingredients except the coriander. Stir well to combine.
If doing pot in pot rice, add a tall trivet to the instant pot and add the rice to a suitable container with 650ml of boiling water. Put the rice on the trivet.
Put the lid on the instant pot. Set on high pressure for 7 minutes.
Leave under pressure for 9 more minutes. Release any remaining pressure and when the pin drops, remove the lid.
Remove the rice and the trivet and stir the tikka masala together.
Serve over rice or naan bread garnished with the coriander (cilantro).