I try to find the largest flat cut corned beef I can find.
Remove corned beef from packaging and wash off all the thick juices. That's just the brine they use don't worry. Set the seasoning packet aside.
Place corned beef on trivet with handles and lower into your pressure cooker
Pour about two cans of beer into the pot. You will want the corned beef to be at least half covered with beer, but not completely submerged. *See beer notes below
Don't worry about the foaming beer or carbonation. That doesn't affect pressure cooking at all. It's perfectly safe. The beer goes flat during cooking just like it does on the stove.
Sprinkle seasoning packet on top. If you are like me and prefer to make your own pickling spices feel free to do that. The seasoning packet in the meat isn't always enough. If you don't like the seasoning packet, skip it. Your corned beef will still be great!
Set your pot to Pressure Cook on High Pressure 3-4 lbs. 60 min for a sliced roast; and 80 min for a shredded roast4-5 lbs. 75 min for a sliced roast; and 100 min for a shredded roastAlways let your meat sit for a full 20 minute NPR. A long natural release is very important for meat in a pressure cooker especially tough cuts like brisket. Release the rest of the pressure in the pot if there is any, and open your lid. Carefully lift your corned beef out of the pot on the trivet with handles and set aside to cool.
Your pot and the liquid are still hot. Add your halved potatoes on the bottom, then carrots, and cabbage chopped pieces on top. Put your lid back on and set your pot to Pressure Cook for 4 min and QR. NOTE: If you like your cabbage more firm, cut it into wedges. If you like your cabbage very soft, chop it into pieces.
Scoop out your veggies with a slotted spoon or spider and move them to a platter. Slice your corned beef and add that to your platter as well. Serve with brown bread, butter, and mustard.