In a large Dutch oven, place the corned beef brisket along with the seasoning packet that typically comes with it. Pour in the stout beer and add enough water to completely cover the beef. Bring the pot to a gentle boil over medium-high heat, then reduce the heat to low. Allow the meat to soften and infuse with flavor for about 4 to 5½ hours.

Once your corned beef has been simmering, add the cinnamon sticks, garlic cloves, bay leaves, and optional chili pepper into the pot. Cover the pot and allow the mixture to continue simmering.

After the corned beef is tender, carefully remove it from the pot and set it aside on a cutting board. Let it rest for at least 10 minutes before slicing against the grain into thick, juicy pieces.

In the same pot, bring the heat back up and add the small red potatoes and large carrots. Cook these hearty vegetables with the lid on for about 20 minutes.

Next, incorporate the chopped green cabbage into the pot with the potatoes and carrots. Cook for an additional 10 minutes, or until all the vegetables are tender.

Arrange the sliced beef on a platter and spoon the colorful vegetables alongside. Optionally, serve with whole grain or Dijon mustard.