In a large pot, combine 10 cups cold water, kosher salt, brown sugar and pink curing salt (if using). Warm gently over low heat, stirring until the salt and sugar dissolve (do not boil). Remove from heat and cool to room temperature, then chill in refrigerator until cold (about 1–2 hours).

Add aromatics

Once the brine is cold, stir in pickling spice, black peppercorns, mustard seeds, crushed garlic, allspice berries, bay leaves and smashed ginger. For more flavor, tie whole spices in a muslin bag or place loose into the brine.

Submerge brisket

Place the trimmed brisket in a nonreactive container or a resealable 2-gallon plastic bag. Pour the chilled brine over the meat, ensuring it is fully submerged. If needed, weigh it down with a plate. Seal the bag or cover the container and refrigerate.

Cure

Let the brisket cure in the brine for 5–7 days in the refrigerator. Turn the meat every 24 hours to ensure even curing and flavor distribution. The pink curing salt is optional but helps retain color and prevents bacterial growth.

Rinse and prepare to cook

After curing, remove the brisket from the brine and discard the brine. Rinse the brisket under cold running water to remove excess salt and surface spices. Pat dry with paper towels.

Simmer the corned beef

Place the rinsed brisket in a large pot and cover with fresh cold water (about 8–10 cups). Add 1–2 tablespoons of the reserved pickling spice or a spice bag for cooking. Bring to a gentle simmer over medium heat, then reduce heat to low to maintain a bare simmer. Skim off any foam that rises to the surface.

Cook until tender

Cover partially and simmer gently for 2.5–3.5 hours, until the brisket is fork-tender and an instant-read thermometer inserted into the thickest part reads about 190–205°F (88–96°C). Cooking time depends on thickness and whether you used point or flat cut.

Vegetables & Serving (optional)

Add vegetables

During the last 30–40 minutes of cooking, add the halved onion, carrots and potatoes to the pot. Add the cabbage quarters in the last 15–20 minutes so they stay tender-crisp. Continue to simmer until vegetables are cooked through.

Rest and slice

When the brisket is tender, remove it from the pot and transfer to a cutting board. Let rest 10–15 minutes to allow juices to redistribute. Slice thinly against the grain for the flat cut (or across the grain for the point cut) for best tenderness.

Serve

Arrange sliced corned beef with the cooked vegetables on a platter. Spoon some cooking liquid over the meat to keep it moist. Sprinkle chopped parsley and serve with Dijon or hot mustard on the side.

Storage

Refrigerate leftover corned beef in an airtight container for up to 4–5 days. Leftover meat can be reheated gently in some reserved cooking liquid or used to make corned beef hash. Brine should be discarded and not reused.

Pickling Spice Blend (if making your own)

Toast the whole coriander, mustard seeds, black peppercorns and allspice briefly in a dry skillet over medium heat for 1–2 minutes until fragrant. Cool, then coarsely crush with a mortar and pestle or spice grinder. Mix with crumbled bay leaf and optional ground coriander and red pepper flakes. Use 3 tablespoons of this blend in the brine and reserve 1–2 tablespoons for cooking.