Cook meat: Put the corned beef, beef broth, stout, onion, garlic, and bay leaves into the pressure cooking pot. Lock the lid in place. Select High Pressure and set the timer for 90 minutes. Once done, allow a natural pressure release for 10 minutes, and then do a quick pressure release to release any remaining pressure.
Set aside roast: Remove the roast from the pressure cooking pot and transfer to a plate. Loosely cover the corned beef with aluminum foil until ready to serve. Scoop all of the solids out of the pot and discard, leaving only the broth.
Cook potatoes: Add the potatoes to the cooking pot, cover, lock lid in place, and cook on high pressure for 3 minutes. Instant release pressure so you can open the lid, add the carrots and cabbage, and then cook on high pressure for 1-2 minutes (depends on how soft you like your carrots). Quick release pressure when done.
Serve: To serve, arrange the cabbage, potatoes, and carrots on a platter. Slice the corned beef against the grain and add to the platter. Ladle the cooking liquid into a gravy boat and serve alongside the meal.