Step 1
Preheat oven to 325 degrees F (165 degrees C).
Step 2
Heat the vegetable oil in a large Dutch oven over medium-high heat until very hot and brown the meat in 2 batches stirring to brown the cubes on all sides. Return all the meat to the Dutch oven sprinkle with flour and stir lightly to coat the meat with flour. Stir in onion carrots dark beer bay leaves thyme 1 teaspoon salt 1/2 teaspoon pepper garlic and Worcestershire sauce. Bring the mixture to a boil and cover.
Step 3
Place the Dutch oven into the preheated oven and cook for 45 minutes; uncover stir the stew and cook until the beef is very tender and the liquid is reduced by half about 45 more minutes.
Step 4
Place the bacon in a large deep skillet and cook over medium-high heat turning occasionally until evenly browned about 10 minutes. Drain the bacon slices on a paper towel-lined plate. Crumble the bacon and set aside.
Step 5
About 30 minutes before the stew is ready make the colcannon: Place the potatoes into a large pot and cover with salted water. Bring to a boil then reduce heat to medium-low cover and simmer until tender about 20 minutes. Drain and allow to steam dry for a minute or two.
Step 6
Place the cabbage into a microwave-safe bowl and add 1 or 2 tablespoons of water. Cover and microwave on High for about 2 1/2 minutes; uncover (watch out for steam) and stir the cabbage. Cover and microwave for about 2 1/2 more minutes until the cabbage is slightly tender but not mushy. Drain excess liquid and set the cabbage aside covered.
Step 7
Place the potatoes into a large bowl and add milk butter 1/2 teaspoon of salt and 1/4 teaspoon of pepper. Beat the potatoes with an electric mixer until smooth and creamy. Stir in the cabbage crumbled bacon and parsley until well combined.
Step 8
To serve place a scoop of colcannon onto a plate make a hollow and fill with braised beef stew.