How to Make It
Heat Instant Pot on High sauté setting. Stir together brown sugar, dry mustard, black pepper, ground cloves, and crushed red pepper in a small bowl. Rub spice mixture on corned beef.
Heat olive oil in Instant Pot. Add brisket, fat side up, and cook, untouched, 3 minutes. Flip brisket over; add beef stock, vinegar, garlic, and bay leaves. Place cabbage and onion pieces around brisket. Cover, close valve, and set to high pressure for 40 minutes. Carefully release pressure, and remove lid.
Transfer brisket and cabbage to a serving platter, cover and let rest 10 minutes. Shred beef, and cover to keep warm.
Press cancel, and set to sauté; bring cooking liquid to a boil. Add potatoes and carrots, and simmer until potatoes are tender, about 15 minutes.
Using a slotted spoon, transfer vegetables to a large bowl; add butter, and toss gently to coat. Add vegetables to platter with corned beef and cabbage, Pour cooking jus over beef and vegetables; sprinkle with fresh dill. Serve with mustard.