Clean, rinse and pat the corned beef dry with papper towel. Set aside. Remove the the onion outer dry layer and cut into quarters. Place onion, garlic, spice seasoning (that came with the corned beef), corned beef and broth into the cooker.
Place the lid on. Pressure cook on high for 90 minutes and natural release for 15 minutes. Follow the manufacture instructions for releasing the pressure. Remove the lid.Note: cook on high for 30 minutes per-pound and natural release for 15 minutes.The last 15 minutes before removing the lid: Clean and cut the potatoes into quarters. Chop the carrots top and tips off then peel and slice into halves crosswise. Remove the cabbage core/stem and cut into 4 wedges. Discarded the core.
Remove the corned beef, place it on a plate and cover/tent with aluminum foil until ready the eat. Remove the onions and garlic. In this order: place potatoes, carrots and cabbage on top in the cooker.
Place the lid on. Pressure cook on high for 5 minutes and natural release for 5 minutes. Follow the manufacture instructions for releasing the pressure. Remove the lid and press the cancel button. Remove the cabbage, potatoes and carrots from the cooker. When ready to eat, slice meat across the grain.