Place 2 pounds boneless, skinless chicken thighs (cut into bite-sized pieces) on cutting board. Sprinkle generous amounts of salt and freshly cracked black pepper onto chicken pieces, then flip chicken over and repeat on other side.
Set Instant Pot to Sauté mode. Add 1-2 tablespoons neutral-flavored oil to Instant Pot insert and heat insert until oil is hot and shimmery.
Add seasoned chicken to Instant Pot. Cook 5 minutes, stirring chicken occasionally, until chicken is lightly seared on all sides.
Add bourbon sauce mixture to Instant Pot. Stir to fully coat chicken in sauce, making sure to scrape up any browned bits of chicken that may have stuck to bottom of insert.
Secure lid on Instant Pot and lock lid with valve in Sealing position. Set Instant Pot to Manual High Pressure, then set cook time to 2 minutes. Instant Pot will come to pressure, then 2-minute cook time will begin.
While Instant Pot pressurizes, add 2 tablespoons cornstarch and 2 tablespoons cold water to small mixing bowl. Whisk vigorously to fully incorporate ingredients into thick slurry mixture. Set aside.
When 2-minute cook time ends, carefully Quick Release internal pressure. Use caution as any escaping steam will be very hot.
Use slotted spoon to remove all chicken from Instant Pot and place chicken in large bowl. Set chicken aside.
Add cornstarch slurry to Instant Pot insert. Whisk slurry and sauce together until well combined, then set Instant Pot to Sauté mode. Bring mixture to boil.
Once boiling, allow mixture to boil 30 to 60 seconds or until sauce has thickened.
When satisfied with sauce consistency, turn Instant Pot off and return chicken to insert. Stir to fully incorporate chicken into sauce.