To Corn Beef:
Add water to a large stock pot and stir in salt, allspice, cloves, bay leaves, cinnamon, peppercorns, mustard seeds, coriander, and ginger. Cook over medium high heat until the salt dissolves. Remove from heat and allow to cool to 45 degrees. Add ice if needed.
Once cool, place brine and brisket in a large zip top bag. Seal, making sure to remove as much air as possible. Place bag in a large casserole dish and lay flat in fridge for 10 days. Be sure to check daily to ensure the meat is completely covered with the brine.
Thoroughly rinse corned beef with cool water and discard brine. Place corned beef in a large stock pot and fill with water until the meat is covered by one inch (roughly 8–12 cups). Add bay leaves, allspice, cinnamon, cloves, salt and pepper and stir to combine.
Place pot over high heat and bring to a boil, lower heat to a simmer, cover, and cook for 2-1/2–3 hours or until meat is fork tender. Add carrots, celery, and garlic and cook uncovered for 12–15 minutes. Add cabbage and cook an additional 12–15 minutes or until tender.
Remove bay leaves, shred or slice corned beef against the grain, and serve immediately w/ cooked veggies and broth (optional).