Step 1

Preheat the oven to 275 degrees F. Mix the fennel seeds, sage, cayenne, 1 tablespoon salt and 1/2 teaspoon black pepper in a small bowl. Rub the spice mixture all over the brisket, pressing it into the meat to make sure it sticks well.

Step 2

Mix the beef stock or broth, balsamic vinegar, brown sugar and garlic in a large liquid measuring cup and set aside.

Step 3

Heat the olive oil in a Dutch oven or large heavy-bottomed pot with a lid over medium-high heat. Add the brisket fat-side up and cook until golden brown and no longer sticking to the bottom of the pot, 4 to 5 minutes. Flip and cook the other side until it is golden brown and some of the fat has rendered, 2 to 3 minutes. Remove the brisket to a plate and lower the heat to medium.

Step 4

Add the onions, carrots and 1 teaspoon salt and cook, stirring occasionally and scraping up any browned bits from the bottom of the pot, until the onions are softened and starting to caramelize, 7 to 8 minutes.

Step 5

Add the balsamic mixture and tomatoes to the pot and bring to a boil. Return the brisket to the pan and nestle it into the sauce and vegetables fat-side up. Cover the pot, transfer to the oven and braise until the brisket is tender but not shredding or falling apart, about 3 hours 30 minutes. A fork should easily pierce through the meat.

Step 6

Remove from the oven, uncover and let the brisket rest in the pan for 30 minutes. Remove the brisket to a cutting board. Bring the vegetables and sauce to a boil over medium-high heat and cook until slightly thickened, 12 to 15 minutes. Thinly slice the brisket across the grain and place on a platter. Spoon the vegetables and sauce over the top and serve.