Place brisket in Instant Pot (fat side down) with broth, onions, garlic, thyme, and seasoning packet.
Lock lid and cook at high pressure for 75 minutes.
Once cook time is complete, allow pressure to release naturally (about 40 minutes). Then remove brisket from pot, cover with foil to keep warm, and allow to rest.
Using a fine mesh strainer, pour liquid into separate container, then return to pot. Discard the aromatics.
Add carrots, potatoes, and salt to pot, then top with cabbage wedges. Lock lid and cook for 0 (zero) minutes at high pressure. Once cook time is complete, quick-release pressure.
Do not stir, but carefully remove each cabbage wedge individually onto your serving dishes, followed by other veggies.
When it’s time to serve, be sure to cut the brisket across the grain to keep it from becoming chewy. Serve together and enjoy!