Step 1

A note on the meat: The original recipe calls for “boned and rolled beef brisket,” a cut that’s common in the U.K. but not available in the U.S. Instead, ask your butcher to roll a 5½ lb. untrimmed flat-cut beef brisket for you. While the meat will be slightly different, the cooking method—low, slow, plenty of liquid—will yield the same successful results, says Heather Marold Thomason of Primal Supply Meats.If your meat comes unrolled, you can roll it yourself: Turn it over so that the fatty side is against your cutting board. Roll it up into a thick log. Tie meat at 1" intervals with kitchen twine—double-knot each tie for extra security. Make sure that you roll it so that the grain runs the length of the roast—that way, when you slice it, you’ll be cutting against the grain.

Step 2

Preheat oven to 350°. Stir 2 (heaping) Tbsp. rose harissa, 1 Tbsp. Diamond Crystal or 1¾ tsp. Morton kosher salt, 1 tsp. ground cinnamon, 1 tsp. ground cumin, 1 tsp. ground fenugreek, 1 tsp. ground turmeric, a generous amount of freshly ground black pepper, and 3 cups water in a medium bowl until evenly combined.

Step 3

Place brisket in a Dutch oven or an ovenproof casserole dish with a lid and pour spice mixture over. Roast, uncovered, basting every 30 minutes or so, for 2 hours.

Step 4

Cover pot and bake, basting meat every 30 minutes, for another 2 hours. Remove lid and roast brisket until deeply brown and an instant-read thermometer inserted into thickest part registers 195°–205°, about 1 hour. Let rest in pot 30 minutes, then slice against the grain. Serve with any liquid in pot spooned over.

Step 5

Do ahead: Brisket can be cooked 3 days ahead. Let cool; cover and chill.