First, move the Instant Pot to the "Saute" function. Add in the olive oil and throw in the onions. Cook this for around 2 minutes.
Add in your Brussel sprouts and then cook for about 1 minute. Add in the pepper and salt, and add the vegetable broth.
Close the lid on the Instant Pot and seal the valve.
Cook on "Manual" high pressure for 3 minutes. It should take about 15 minutes for the pressure to get high.
Once the timer is up, quick release the pressure. Remove the lid and serve your Brussel sprouts.