Step 1

Adjust oven rack to the middle position and preheat oven to 300 degrees. In a Dutch oven, combine beef brisket, chicken broth, water, chopped carrots, celery, onion, bay leaves, peppercorns, thyme and allspice berries. Cover and bake until a fork inserted into brisket goes in and out easily, about 4 1/2 to 5 hours.

Step 2

Transfer meat to a 9-inch by 13-inch baking dish. Strain liquid through a fine-mesh strainer into a large bowl and discard the solids. Skim fat from liquid. Pour 1 cup of the cooking liquid over the beef, cover the dish tightly with aluminum foil, and allow to rest for 30 minutes.

Step 3

Return the remaining cooking liquid to the Dutch oven, add the butter and bring to a simmer over medium-high heat. Add the potatoes and simmer until softened, about 10 minutes. Add the carrot halves and cabbage, cover, and cook until tender, about 10 to 15 minutes. Using a slotted spoon, transfer the vegetables to a serving platter, seasoning with salt and pepper to taste.

Step 4

To serve, slice the brisket across the grain in 1/4-inch slices. Arrange slices on a platter. Using a slotted spoon, transfer the cooked vegetables to the platter and lightly moisten with cooking liquid as needed until served. Garnish with fresh parsley if desired.