In a mixing bowl, combine garlic powder, onion powder, chili powder, paprika, salt, and pepper. Add chicken and toss with your hands to coat the chicken with spices.
Select Sauté and preheat the Instant Pot. When hot, add the butter and oil and stir until butter is melted. Briefly sauté the chicken a few pieces at a time on both sides and remove to a plate.
When all the chicken has been sautéed. Add the chicken stock and chicken to the pot.
Lock the lid in place. Select Pressure cook and program for 3 minutes, followed by quick pressure release.
In a small bowl, dissolve corn flour in water. Push chicken to one side of the pot and add corn flour mixture and stir to combine.
Select Sauté and stir constantly until sauce thickens. Turn off pressure cooker and gradually stir in heavy cream.
Serve chicken and sauce over spaghetti sprinkled with parsley. Enjoy!