01 - Rinse the halal corned beef brisket under cold running water to remove excess brine. Transfer to a large stockpot or Dutch oven.
02 - Pour in 4 cups water. Add bay leaf, black peppercorns, cloves, mustard seeds, and cinnamon stick. Ensure brisket is mostly submerged, adding more water if necessary.
03 - Bring to a gentle simmer over medium heat, skimming off any foam that rises to the surface. Reduce heat to low, cover tightly, and cook for 2 hours.
04 - Add carrots, parsnips, potatoes, rutabaga or turnip, and onion to the pot. Cover and continue simmering for 45 minutes.
05 - Add cabbage wedges, cover, and cook an additional 20-30 minutes until both meat and vegetables are fork-tender.
06 - Remove brisket to a cutting board and let rest for 10 minutes. Slice against the grain into thin strips for maximum tenderness.
07 - Arrange sliced brisket and vegetables on a serving platter. Ladle broth over the top, garnish with chopped parsley, and season with salt and pepper to taste. Serve hot with mustard or horseradish.