In a small bowl, whisk together coconut milk, tomato paste, grated fresh ginger, minced garlic, spices, and salt.
Cut green beans and cauliflower into bite-sized pieces. Dice onion into small pieces. Cut chicken into small cubes.
Spray the inside of the Instant Pot with cooking spray. Layer onion, then veggies, then chicken. Pour the coconut-spice mixture over the top and agitate just a little so it evenly coats everything. Cube the butter and sprinkle on top.
Close the lid of the Instant Pot and make sure the vent is sealed. Push "manual" and make sure high pressure is selected, then set the time to 10 minutes.
Once done cooking, press "Cancel" to turn off the heat, then open the vent to do a quick release of the pressure.
Add Greek yogurt and mix well. The bottom may have a layer of cooked sauce, so just avoid scraping this if you do not want to mix it in.