In a medium bowl, whisk together soy sauce, vinegar, honey, and (if using) mirin/sherry
Turn the instant pot to saute mode and heat the sesame oil. Add the chicken and season with salt and pepper to taste. Saute for 2-3 minutes, until lightly brown
Add garlic and ginger and cook for another 20-30 seconds. Pour in half of the sauce, uncooked rice, and 1 cup of water
Turn off saute mode, put the lid on the instant pot, and cook on high pressure for 3 minutes. Allow to natural release for 10 minutes
Remove lid and go back to saute mode. Add peppers, carrots, broccoli, and edamame
Whisk cornstarch and 3 tbsp water together, then add to reserved sauce. Drizzle in desired amount (I generally put it all in). Cook until vegetables are tender, about 5 minutes
Garnish with sesame seeds and scallions to serve