Cut the cabbage in to 8 sections. See post for more details. Add 1 cup of water and 1/4 cup balsamic vinegar to the inner pot. Place the cabbage sections on the bottom of the inner pot. Add in the extra seasoning blend as well as the packet of seasonings that comes with the corned beef.
Place the corned beef fat side up on top of the cabbage. Put the pressure lid on and set the Ninja Foodi to high pressure for 7 minutes. When the time is up, immediate release the pressure.
Remove the corned beef and set on a cutting board. Remove the cabbage and put in a bowl. Place the rack in the low position into the inner pot and place the corned beef on the rack, fat side up. Put the pressure lid back on and set the Ninja Foodi to high pressure for 45 minutes. When the time is up, allow to natural release for 10 minutes. Remove the rack with the corned beef out and set to the side.
Peel and cut carrots into thirds. Cut potatoes into quarters. See post for details. Place the carrots into the bottom of the Ninja Foodi and place the potatoes on top. Set the corned beef on top of the potatoes and put the pressure lid on. Set the pressure to high and cook for 2 minutes. All the Ninja Foodi to naturally release its pressure for 10 minutes.
Make the glaze: combine the 1/4 cup of balsamic vinegar, brown sugar, and mustard in a small bowl.
Remove the corned beef and set to the side. Remove the carrots and potatoes and place in a large mixing bowl. Pour the juice from the inner pot into the bowl to keep the carrots and potatoes warm.
Place the cabbage around the sides of the fry basket. Place the corned beef in the center. Pour the glaze over the top. Set the Air Crisp function to 400° F and Air Crisp for 20-25 minutes. Remove corned beef and set on a cutting board to rest for 15 minutes.
Move the cabbage around a bit and add in potatoes and carrots to the air fry basket. Air Crisp on 400° F for 15 minutes.
Slice the corned beef against the grain. See video for more details. Serve with cabbage, potatoes, and carrots. Enjoy!