We will be using the pot-in-pot method to cook the rice and the chicken at the same time. We will finish the chicken in the oven for the best flavor.
Place chicken in Instant Pot®. Pour marinade over chicken. Top chicken with a metal steamer rack. Combine rice and water in an oven safe bowl that will fit inside your Instant Pot®. Place bowl on top of steamer rack.
Cover and set to sealing. Program for manual-high, and set time for 6 minutes. When time is up, allow natural pressure release for 10 minutes before releasing steam manually. Preheat oven to 450.
Remove rice bowl, and fluff rice with fork. Set aside.
Remove chicken with a slotted spoon and place on a baking sheet lined with parchment paper.
If desired, for thicker sauce, combine 1 tablespoon cornstarch and 3 tablespoons water. Add slurry to sauce in Instant Pot® and stir to combine. Program for sauté. Heat to boiling and simmer until thick. (If no thicker sauce is desired, proceed to next step.)
Brush sauce over chicken. Bake at 450 for 5-8 minutes.