When you’re ready to prepare your meal, turn on your Instant Pot, set it to sauté, and add in the avocado oil.
When the Instant Pot has warmed up, it’s time to start the curry sauce. Add the onions, ginger, garlic, garam masala, coriander, cumin, chili powder, turmeric and salt. Sauté for about 4-5 minutes.
Turn off the sauté setting. Pour 3/4 cup of water into the pot (with the onion mixture) and use a wooden spoon or spatula to deglaze the bottom. In other words, scrape up any browned bits. If you don’t, there’s a good chance your Instant Pot will give you a “burn notice” error during pressure cooking.
After you’ve deglazed the pot, add in diced tomatoes, tomato sauce, and chicken including all of the yogurt marinade. Stir until everything is well combined.
Lock the lid in place and set the valve to the "sealing" position. Cook on high pressure for 7 minutes.
After the cooking time has been reached, allow the pressure to naturally release. If you’re in a rush, you can use the quick release method, too. I use a long-handled spoon to move the release valve so that I’m able keep my hand far away from the steam. When the float valve drops, carefully unlock and remove the lid.
Set the Instant Pot to sauté and stir in cream. The sauté setting will help with the next step, which is thickening the sauce.
Make a slurry of 5 tablespoons arrowroot powder mixed in 4-5 tablespoons of water and pour the mixture into the pot. Stir well and then continue stirring frequently until it thickens - the process should take a couple of minutes. Serve with gluten-free flatbread or over basmati rice or cauliflower rice.