• Preheat your oven to 325 degrees F (165 degrees C).

For the Stew:

• In a large Dutch oven, heat oil over medium-high heat until it's very hot.
• Brown the beef in two batches, cooking and stirring until it's nicely browned.
• Put all the beef back into the Dutch oven, sprinkle with flour, and stir gently to coat the meat.
• Add beer, onion, carrot, bay leaves, Worcestershire sauce, garlic, thyme, salt, and pepper to the pot and stir.
• Bring the mixture to a boil, then cover the Dutch oven.
• Place the covered Dutch oven in the preheated oven and bake for 45 minutes.
• Uncover, stir the stew, and continue baking until the beef is tender and the liquid is reduced by half, about 45 more minutes.

For the Colcannon:

• Cook bacon in a large skillet over medium-high heat until evenly browned, about 10 minutes.
• Drain the bacon on a paper towel-lined plate, then crumble it and set it aside.
• Sauté the cabbage in the bacon grease, then set it aside.
• About 30 minutes before the stew is done, put the potatoes in a large pot and cover them with salted water.
• Bring the water to a boil, then lower the heat to medium-low, cover, and simmer until the potatoes are tender, about 20 minutes.
• Drain the potatoes and let them steam dry for 1 to 2 minutes.
• Transfer the potatoes to a large bowl, add warm milk, butter, salt, and pepper.
• Beat with an electric mixer until the mixture is smooth and creamy.
• Stir in the sautéed cabbage, crumbled bacon, and parsley until everything is well mixed.

To Serve:

• coop some colcannon onto a plate, make a hollow in the center, and fill it with beef stew.