Turn Instant Pot onto saute and add oil. Heat until hot. When hot, add chicken (salt and pepper to taste if you wish) and slightly brown.
While chicken is cooking, in a small bowl whisk together soy sauce, hoisin sauce, vinegar, brown sugar, ginger, garlic, water, and sesame seeds.
When chicken has been slightly browned, add sauce mixture.
Close Instant Pot and cook on manual high pressure for 5 minutes. When timer is done perform a quick release of pressure.
Open Instant Pot and add the broccoli and red pepper.
Close Instant Pot and cook on high pressure for 0 minutes (this is a real thing, you just keep hitting the negative time when on manual until the timer reads 0).
While Instant Pot is cooking, in a small bowl whisk together corn starch and ¼ cup of water and set aside.
When timer is done perform a quick release of pressure.
Turn the Instant Pot back on to saute and bring to a simmer. When simmering add corn starch and water slurry and stir until well combined.
When sauce had thickened add cashews and stir.
Serve over rice and enjoy!
Notes
Leftovers will keep in the refrigerator for 3 days.