Rinse corned beef and pat it dry with paper towels.
Wash all your veggies.
Cut cabbage into 4 quarters.
Slice your onions and cut potatoes in half.
Put the olive oil into the bottom of the dutch oven and bring to a medium heat.
Add the corned beef brisket into your dutch oven and brown all sides of the brisket. This should take about 3-4 minutes.
Take the brisket out and set aside. Add the carrots and onions to the bottom of the dutch oven and then return the meat to the pot.
Sprinkle in the included seasoning packet.
Pour beer into the dutch oven. Then pour water until it reaches to the top of the meat.
Cover and bring to a boil over high heat (approximately 8 minutes).
Lower the temperature - between low and medium - and cook for 3 ½ hours.
Add potatoes in with the meat and vegetables. If the cooking liquid is below the top of the meat, add more water or beef broth just enough to cover most of the meat. Cook for another hour.
Next, add cabbage and place the lid back on top. Then cook for an additional 30 minutes.
Remove corned beef brisket from the Dutch oven and place on a cutting board. Slice against the grain and add it back to the pot.
Move the dutch oven to the table and serve with horseradish sauce.
