3 to 7 - pound corned beef brisket (buy big – it shrinks)
1 1/2 cups water/beef broth (or part beer)
5 cloves garlic, peeled
1 onion, coarsely chopped
the seasoning pack the corned beef came with
2 lbs. red-skinned potatoes, quartered, skin on
4-6 carrots, in large chunks
1 head green cabbage, cut into wedges
Rinse the corned beef under cold running water to remove excess salt and then pat it dry. Pour the water, broth and/or beer in the Instant Pot and toss in the garlic and diced onion. Place the trivet on top of the onions and the corned beef on the trivet. Sprinkle the meat with the contents of the seasoning packet if it came with one. If it didn't, don't worry about it. The meat is already well seasoned.
Close the lid and make sure the valve is set to Sealing. Push the Pressure Cook (or Manual) button. Adjust the time using the + and - buttons to get to 75 minutes. Now go have a cup of tea or something and bask in the satisfaction a little. This is going to be GREAT.
When it beeps that it's done, just leave it for 15 minutes natural release. Use this time to prepare the vegetables. Be sure to leave the core attached as you cut the cabbage into wedges. It helps hold the leaves together.
After the 15 minutes natural release, flip the valve from Sealing to Venting to release any remaining pressure. When the pin drops, open the pot. Lift the trivet out with the corned beef on it. Gently transfer the corned beef to a warmed platter (it will be VERY tender) and cover it with tin foil.
This is not traditional but if desired, put the corned beef on a foil-lined baking sheet and brush with a mixture of 3 Tbsp good quality mustard and 2 Tbsp Brown sugar. Then brown under the broiler for a few minutes for a delicious glaze.
There may be a lot of liquid left in the pot. Remove all but about 1 1/2 cups. (Save that liquid... it's GOLD as a soup base.)
Put the trivet back in the pot and put the potatoes, the carrots and cabbage wedges on it in that order. Close the pot, set it to Sealing again and hit Pressure Cook (Manual). Use the +/- buttons to take it down to 4 minutes. When it beeps that it's done, flip the valve to Venting for a quick release.
Put the cabbage and carrots on the platter. (Test the potatoes for doneness with a paring knife while they are still in the pot. If not quite done, close the pot and do another 2 minutes.)
Slice the corned beef on the platter surrounded by the potatoes, carrots and cabbage. Garnish with some fresh parsley sprigs for a dash of Irish green on St. Patrick's Day. Or shamrocks, if you have 'em.