Sauté the Aromatics: Set the Instant Pot to Sauté mode on More or High. Heat the vegetable oil and butter. Once melted, add the diced onion and cook until softened and slightly browned, about 2-3 minutes.
Cook the Chicken: Stir in the minced garlic and chicken pieces. Sauté for another 2-3 minutes, until the chicken starts turning pinkish-white on the edges.
Deglaze & Add Rice: Pour in ½ cup of the chicken broth, scraping the bottom of the pot to loosen any browned bits. Add the rinsed rice and remaining 1½ cups of broth, stirring to combine.
Pressure Cook: Secure the Instant Pot lid and set the valve to sealing. Select Manual or Pressure Cook on High Pressure for 3 minutes. Once done, allow for a 10-minute natural release, then perform a quick release to release any remaining pressure.
Make the Nashville Hot Sauce: While the rice cooks, prepare the sauce by whisking together hot sauce, vegetable oil, brown sugar, cayenne pepper, paprika, chili powder, and garlic powder in a bowl.
Finish & Serve: Fluff the rice with a fork, then pour in the Nashville hot sauce. Stir well until the chicken and rice are evenly coated in the spicy sauce. Garnish with sliced scallions and serve immediately.