Prepare the ingredients: Wash and chop the broccoli into florets, dice the bell pepper and onion, and mince the garlic and ginger.
Turn the Instant Pot to the sauté mode. Add the vegetable oil and let it heat for a minute.
Add the onions, bell peppers, garlic, and ginger to the pot. Sauté for about 3-4 minutes until the vegetables start to soften.
In a mixing bowl, combine the soy sauce, rice vinegar, hoisin sauce, brown sugar, cornstarch, water, and red pepper flakes. Stir until well mixed.
Add the broccoli florets to the Instant Pot, then pour the sauce mixture over the vegetables. Stir to combine.
Close the lid of the Instant Pot and set the valve to sealing. Cook on high pressure for 3 minutes.
Once cooking time is complete, carefully quick-release the pressure.
Open the lid and stir the contents. Let it sit for a minute to thicken, if desired.
Serve immediately, garnished with chopped roasted peanuts.