Preheat the Oven: Position a rack in the lower third of the oven and preheat it to 325°F (165°C). This temperature is ideal for slow braising, allowing the brisket to become tender without drying out.

Season the Brisket: Pat the brisket dry with paper towels. Season both sides evenly with the kosher salt and black pepper. Let it stand at room temperature for about 15 minutes while the Dutch oven heats. This helps the seasoning penetrate the meat better.

Brown the Beef: Heat the neutral oil in a 7-quart Dutch oven over medium-high heat. Add the brisket fat-side down and sear for 5 to 6 minutes, until deeply browned. Turn and brown the second side for another 5 minutes. Transfer the brisket to a large plate. Browning adds depth of flavor and creates a nice crust.

Cook the Onions and Celery: Reduce the heat to medium. Add the onions and celery to the Dutch oven. Cook for 10 to 12 minutes, stirring occasionally and scraping up the browned bits, until the onions are soft and beginning to turn golden. If the bottom begins to scorch, add 1 tablespoon of water. This step builds the base flavor for the gravy.

Add the Aromatics: Stir in the garlic, tomato paste, paprika, and thyme. Cook for 1 minute, stirring constantly, until the tomato paste darkens slightly and the garlic becomes fragrant. This enhances the overall flavor profile of the dish.

Deglaze with Wine: Pour in the red wine and scrape the bottom of the pot with a wooden spoon. Simmer for 3 to 4 minutes, until the wine has reduced by about one-third. This process lifts the flavorful bits stuck to the pot and incorporates them into the sauce.

Build the Braising Liquid: Stir in the beef broth, tomato sauce, honey, apple cider vinegar, and bay leaves. Bring the mixture to a gentle simmer. The sauce should taste savory and lightly tangy, with mild sweetness. This balance is crucial for a rich gravy.

Begin Braising the Brisket: Return the brisket to the Dutch oven fat-side up, nestling it into the onions. The liquid should reach roughly halfway up the meat rather than covering it completely. Cover the pot tightly and transfer it to the oven. This ensures even cooking and moisture retention.

Add the Carrots: Braise for 2 hours 30 minutes. Carefully remove the pot from the oven and arrange the carrot pieces around the brisket, pressing them partly into the sauce. Cover and return the pot to the oven. Adding the carrots later prevents them from becoming mushy.

Cook Until Tender: Continue braising for 1 to 1 1/2 hours. The brisket is ready when a fork or thermometer probe slides into the thickest section with little resistance. It will typically register between 195°F and 205°F (91°C and 96°C) when tender. This temperature range is essential for achieving the desired tenderness.

Rest the Brisket: Transfer the brisket to a cutting board and loosely cover it with foil. Let it rest for 30 minutes. Remove and discard the bay leaves. Skim excess fat from the surface of the gravy if needed. Resting allows the juices to redistribute, making the meat more moist.

Slice and Serve: Identify the direction of the meat fibers and slice the brisket across the grain into pieces about 1/4 inch thick. Arrange the slices on a platter and spoon the onion gravy and carrots over the top. Garnish with parsley, if using. Proper slicing technique ensures tender bites.