Turn on the Instant Pot to the sauté setting. Add the olive oil, ground turkey, onion, and garlic. Cook, breaking up the turkey with a spoon, until the turkey is browned and the onion is softened.
Add the cumin, oregano, salt and pepper and mix evenly into the turkey to coat. Add the beans, rotel, green chilies, chicken broth amd corn. Stir until well combined.
Close the lid on the Instant Pot and set the valve to the sealing position. Select Manual or Pressure Cook and set the timer for 15 minutes.
When the cooking cycle is complete, let the pressure release naturally for 10 minutes, then quick release the remaining pressure. Open the lid and turn the Instant Pot back to the sauté mode.
In a small bowl, whisk together the half and half and arrowroot powder. Stir the mixture into the chili. Cook the chili for an additional 3-5 minutes, stirring regularly, until it thickens to a creamy consistency.
Taste and adjust seasonings as necessary and serve with your favorite toppings.
