Add garlic, onion, and bay leaves to Instant Pot® container and pour the broth and water on top. Place the trivet that comes with the Instant Pot® inside the container with the handles positioned up for easy removal.
Place the brisket fat-side down on the trivet and season with salt and black pepper, to taste. Sprinkle the spice packet that came with the brisket on top.
Add the lid and lock into place. Set the vent to “Sealing” and select the “Manual” button. Adjust to the “High” setting and set the cook time to 85 minutes.
When cook time is complete, allow the pressure to release naturally for 10 minutes before doing a quick release on any remaining pressure. Remove brisket by carefully lifting the trivet out by the handles (using potholders) and transfer to a platter. Set aside and keep warm.
Return the trivet to the Instant Pot® and add the carrots, potatoes, and cabbage on top. Cover and lock lid into place. Set the vent to “Sealing” and select the “Manual” button. Adjust cook time to 3 minutes.
When cook time is complete, allow the pressure to release naturally for 5 minutes before doing a quick release on the remaining pressure.
Transfer the cooked vegetables to the serving platter with the corned beef. Slice the beef against the grain and serve immediately along with the vegetables. Enjoy!