Place the corned beef brisket in a large pot and cover it with enough water to submerge it completely.

Add the quartered onion and the seasoning packet typically included with the brisket. Bring the pot to a boil over medium-high heat.

Once boiling, reduce the heat to low and let it simmer for about 150-180 minutes, or until the meat is tender.

After the brisket has been simmering for about 120 minutes, add the carrots and potatoes. This allows them to cook through while absorbing the flavors.

Finally, around 20 minutes before serving, add the cabbage wedges to the pot. Cook until all vegetables are tender.

Carefully remove the brisket from the pot and let it rest for a few minutes. Slice against the grain, serve alongside the vegetables, and don’t forget the mustard for dipping.