Pour the water into the inner pot, and place the trivet inside. Place the basket on the trivet. Lock the lid into place. Select Steam, and set the time to 1 minute. Make sure the steam release knob is in the Sealed position.
Put the brussels sprouts into a steamer basket, then lower onto the trivet.
Secure the lid and select Steam function, setting the time to 1 minute.
When the cooking program has finished, perform a quick pressure release then unlock and remove the lid.
Using tongs, carefully transfer the Brussels Sprouts to a serving plate. Discard the water, and wipe the inner pot dry.
Select Sauté on the inner pot, and pour in the oil.
Once hot, add the garlic and sauté for 1 minute, then add the Brussels sprouts, vinegar, salt, and pepper, and sauté for 2 minutes.
Sprinkle with the roasted sesame seeds and serve hot.