Preheat the oven to 300 degrees F.

Rinse the corned beef under cold running water.

Place corned beef in a large Dutch oven.

Add water, bay leaves, peppercorns, allspice, and cloves.

Bring to a boil and skim off any scum.

Cover and braise in the oven for 3 hours and 45 minutes, or until very tender.

Transfer the corned beef to a cutting board and cover with foil.

Add the cabbage and potatoes to the cooking liquid.

Bring to a boil, then simmer for 20 minutes, or until vegetables are tender.

Transfer the cabbage to a platter.

Slice the corned beef across the grain into thin slices.

Lay slices over the cabbage and surround with potatoes.

Ladle hot cooking liquid over the corned beef and season with pepper.

Serve with mustard or horseradish sauce.

For horseradish sauce: mix mayonnaise, sour cream, horseradish, zest, and salt.

Season with pepper and refrigerate for 30 minutes.

For Corned Beef Hash: Mash 1 cup potatoes.

Add remaining potatoes, corned beef, cooking liquid, onion, garlic, mustard, thyme, and nutmeg.

Season and mix well, then refrigerate overnight.

Stir in parsley.

Heat butter in a skillet.

Add hash mixture and cook, stirring, for 30 seconds.

Press into a cake and cook for 4 minutes.

Reduce heat and cook for 6 minutes, until browned.

Flip the hash.

Cook for 3 minutes on the other side.

Reduce heat and cook until browned and crispy, about 5 minutes.

Set aside covered with foil.

For poached eggs: combine water, vinegar and salt in a large skillet and bring to a simmer.

Crack the eggs into separate cups.

Carefully slide the eggs into the skillet and cook, turning occasionally with a spoon, until firm, about 3 to 5 minutes.

Remove and dab with a kitchen towel.

Divide the hash among plates and top with poached eggs.