Add garlic, onion, and bay leaves to the pressure cooker and pour the beer and water/broth on top. Place the trivet inside the pressure cooker with the handles positioned up for easy removal.
Place the brisket fat-side down on the trivet and sprinkle the spice packet that came with the brisket on top.
Cook on high pressure for 85 minutes.
When cook time is complete, allow the pressure to release naturally for 10 minutes then do a quick release of the remaining pressure. Remove brisket, transfer to cutting board and tent with foil.
Add the carrots, potatoes, and cabbage on top of the trivet in the pressure cooker. Cook at high pressure for 3 minutes.
When cook time is complete, allow the pressure to release naturally for 5 minutes then do a quick release of the remaining pressure.
Transfer the cooked vegetables to a serving platter. Slice the beef against the grain and add to the serving platter. Serve immediately.