Put the water in the Instant Pot first and then add your onions, garlic, pickling spice, and thyme. Give this a stir. Now, add your corned beef brisket to the pot.
Place the lid on the Instant Pot and seal. Press the pressure cook button, set to “manual, more”. Set the timer for 85 minutes. When the time is up, press the quick release button and release all the pressure. When the pin drops, it’s safe to open the top. Take the brisket out and let it rest on a platter.
Now, discard all but 2 cups of the liquid in the pot (you can strain this if you like). Add the potatoes, carrots, and cabbage to the 2 cups of liquid in the Instant Pot. Seal the instant Pot. Press the pressure cooker button and set for “manual, more” for 5 minutes. When the time is up, quick release and you’re ready to serve. I like to cut my brisket into ½” slices and serve with the veggies all around. Also, don’t forget to spoon some of that cooking liquid over the meat and veggies. This is so good!
Note: the veggies were very soft and tender. If you like your veggies with a bit more structure, pressure cook for only 4 minutes.