Remove boiling bacon from wrapper and carefully, pull strings away from the meat all around the bacon while leaving the netting intact.
Place bacon in a large stock pot and cover completely with water. Bring water to a slow boil, cover, and reduce heat to medium-low. Simmer bacon for about 1 1/2 hours, or until meat is cooked through and tender when pierced with a fork. Skim any foam that forms off of the top of the water. Note: Bacon should cook for 30 minutes per pound.
On a cutting board, cut the end off of the cabbage, then cut the cabbage into quarters. About 15 to 20 minutes before meat is done, add quartered cabbage to the simmering pot. Cook until cabbage is tender, but not wilted.
When bacon and cabbage are cooked, remove the bacon and place on a cutting board to rest for 10 minutes. Using a slotted spoon, spoon out the cabbage and place on a serving platter. If making the Parsley Sauce, reserve 1/4 cup of the cooking liquid for the recipe.
When bacon has rested, remove netting and cut into 1/4-inch slices. Transfer meat to the serving dish with the cabbage.
In a saucepan over medium heat, melt the butter. Slowly stir in the flour and cook until mixture is smooth and no clumps remain. Change to a whisk, and whisk in the bacon cooking liquid and the hot milk. Bring to a quick boil, whisking constantly, then reduce heat to a simmer, cooking until thickened. If sauce is too thick you can add either more cooking liquid or more hot milk to thin. Add salt and pepper and minced parsley, whisking constantly. Cook only until parsley sauce is smooth and creamy. Serve warm with the boiling bacon and cabbage.
Serving Suggestions: For a traditional Irish meal, serve Boiling Bacon and Cabbage with Parsley Sauce, Irish Boiled Potatoes, and a Guinness or Magners Cider.