1.Turn on your Instant Pot and press saute and medium button then add butter. When butter is melted add cubed chicken, onion, and salt.
2.Cook the chicken halfway for 5 minutes then turn off. Add heavy cream, tomato sauce, garlic, ginger, chili powder, cumin, garam masala, and cayenne into your Instant Pot and mix together well.
3.Put lid on and seal steam valve. Set Instant Pot to manual, pressure, low, for 5 minutes.
4.When done move steam valve slightly to let steam come out slowly. Carefully lift lid. Set to saute low for just a few minutes. Add some of the hot liquid in a small bowl with cornstarch and whisk together, add back into the pot and stir. Sauce will thicken more as it sits. Turn off, add cilantro in, and serve with rice and/or naan.