Step 1

Preheat the oven to 325 degrees F.

Step 2

Pat the brisket dry and sprinkle liberally on both sides with salt and pepper. Heat a roasting pan over 2 burners on medium-high heat. Add the oil and heat until hot. Sear the meat, fat-side down, until golden brown, about 10 minutes. Carefully flip and sear on the second side until golden brown, 7 to 8 minutes. Remove the brisket to a platter or baking sheet. Remove all but 2 tablespoons of fat from the pan.

Step 3

Add the sweet onions to the pan and cook, scraping the bottom, until just starting to brown, 4 to 5 minutes. Add the wine and cook until reduced by about a third, about 4 minutes. Add the chicken broth, garlic cloves and thyme. Return the brisket and any juices to the pan, cover tightly with foil, transfer to the oven and cook for 3 hours.

Step 4

After 3 hours, check to make sure there is still liquid in the pan. If not, add another cup of chicken broth. Re-cover tightly with the foil and cook for another 1 1/2 hours.

Step 5

Arrange the pearl onions and leeks around the meat, re-cover with the foil and cook until the meat is very tender, 1 to 1 1/2 more hours. Carefully remove the meat to a platter.

Step 6

Stir the honey into the roasting pan, place the pan over 2 burners on medium heat and reduce the liquid by about a third, 6 to 10 minutes. Discard the thyme sprigs. Spoon off any oil from the sauce. Season with salt and pepper. At this point you can serve the brisket or refrigerate overnight (see below).

Step 7

Toss the parsley, mint, scallions and shallots with the vinegar in a bowl and season with salt and pepper.

Step 8

Spoon some of the sauce with the sweet onions, leeks and pearl onions onto a large platter. Cut the brisket across the grain into thin slices and lay them on top of the sauce. Spoon over more of the sauce and mixed onions and top with the parsley mixture. Serve the remaining sauce and onions on the side

Step 9

Make Ahead: You can refrigerating the brisket overnight before serving. Remove the sweet onions, pearl onions and leeks from the sauce and refrigerate separately. The fat will harden as the brisket and sauce chill, making it easy to spoon out. To serve, remove the brisket to a cutting board while cold. Thinly slice and return to the sauce along with the mixed onions. Cover and reheat in a 325 degree F-oven for about 45 minutes.