• Remove corned beef brisket from package, and place in large dutch oven-type pot. If the corned beef came with a seasoning packet of spices, empty that over the beef. Add quartered onions, chopped celery ribs, garlic cloves, peppercorns, whole cloves and bay leaves. Next add the beer if you're using it, then add enough cold water to completely cover the meat.
  5 to 6 lb. Flat cut corned beef brisket, 2 medium onions,, 2 celery ribs with leaves,, 3-4 whole garlic cloves,, 8-10 whole peppercorns, 6-8 whole cloves, 2 bay leaves, 1 -12 oz. bottle or can dark beer,, Water to cover
• Bring the pot to a boil, cover, reduce the heat to a rapid simmer, and cook up to 4 hours, or until the internal temperature reaches at least 160F degrees. During this process, turn the meat a couple of times, about every 1 ½ hours.
• After meat is tender and has cooked the appropriate time (or more), remove from water and place on baking sheet or roaster pan to rest, fat side up. Pre-heat oven to 350F degrees.
• Spread fat-top with 1 Tablespoon mustard, covering in a thin layer, using more than called for if your brisket is big. Sprinkle with fresh ground black pepper and garlic salt. Next, generously sprinkle brown sugar on top of mustard layer, being careful not to get sugar on the pan (unless you don't mind your kitchen filling with a burnt sugar smell and some smoke).
  1 Tbsp classic yellow or brown mustard, ¼ cup brown sugar

Let meat rest like this while you prepare the rest of the vegetables:

• Bring the water back to a boil and add the red potatoes, pearl onions, and carrots. Cover, reduce heat to medium and simmer until tender.
  10-12 small whole red new potatoes, 10-20 small frozen white pearl onions, 4-5 large carrots
• Place meat in oven for approximately 15-20 minutes, checking periodically. A nice carmelized crust will begin to form on top of the meat. If the meat begins to burn, tent with foil for last few minutes. While the meat is finishing in the oven, do the following:
• Once the potatoes and carrots are tender, add cabbage and parsley to the water, continue to simmer, covered an additional 10 minutes or so, until the cabbage is tender.
  1 small white cabbage, 3 tbsp fresh parsley
• Turn your vegetables off and:
• Place meat on a serving platter or cutting board. Let rest 15 minutes. Slice thinly, about ¼ inch thick.
• Using a slotted spoon, remove vegetables into a serving bowl.
• Serve meat with horseradish-sour cream mixture, vegetables, Irish Soda Bread and creamy soft butter, if desired.
• Leftover meat is amazing the next day.