Prep your crockpot by spraying non stick cooking spray or lining it with a disposable crockpot liner.
Place your corned beef in the crockpot, pour the seasoning packet that comes with it on top of the meat.
Pour enough water to cover the whole piece of meat. Put the lid on your crockpot and turn it on high.
If you are adding carrots and potatoes wash and cut them up and set them aside. You will want to add them to the crockpot after the meat has cooked for 3 hours.
At the 7 hour mark rinse your cabbage and cut it into wedges. Place the wedges into the crockpot and put the lid back on.
Cook for another hour. At the 8 hour mark check the corned beef and the cabbage to see if it is cooked all the way, if it is not then leave it in for another 30 minutes.
Once it is done cooking remove the beef from the crockpot and allow to cool and set for 5 minutes before cutting. Once cooled and set, slice corned beef into slices.
Remove the veggies in place them in a serving bowl.