Add the beef broth, salt, pepper, and minced garlic to the insert of a 6-8 quart Instant Pot.
Rinse the corned beef under cool water. Place the corned beef brisket on top of the broth mixture.
Sprinkle the corned beef with the pickling spices that came with the brisket.
Close and lock the lid.
Select MANUAL, set to HIGH pressure, and cook for 1 hours and 10 minutes.
When cooking time is complete, allow for a natural pressure release (about 15-20 minutes).
Carefully remove the corned beef from the Instant Pot and set aside on a cutting board to rest.
Add the potatoes, carrots, onions, and cabbage into the remaining juices in the Instant Pot.
Close and lock the lid again.
Select MANUAL, set to HIGH pressure, and cook for 5 minutes.
When finished, carefully quick release the pressure.
Slice the corned beef against the grain and serve with the cooked vegetables and some of the flavorful broth spooned over the top.