Step 1

Preheat the oven to 325°F (160°C).

Step 2

Pat the roast dry with paper towels. Season the roast all over with 1 tablespoon salt and 1 1/2 teaspoons pepper. Place the flour on a plate and dredge the roast in flour, turning to coat all sides, including the ends.

Step 3

In a large Dutch oven over medium heat, warm 2 tablespoons oil. Add the roast and sear, without moving it, until nicely browned, 5 to 8 minutes. Turn and sear the opposite side. Then turn and sear the ends, 4 to 5 minutes each. Using tongs, transfer the roast to a large plate.

Step 4

Add 2 tablespoons oil to the Dutch oven and keep it over medium heat. Add the carrots, onions, celery, leeks, garlic, 1 tablespoon salt, and 1 1/2 teaspoons pepper and cook, stirring occasionally, for 10 to 15 minutes, until tender but not browned.

Step 5

Carefully add the wine and Cognac and bring to a boil.

Step 6

Add the tomatoes, chicken stock, bouillon cube, 2 teaspoons salt, and 1 teaspoon pepper. Tie the thyme and rosemary together with kitchen string and add to the pot. Return the roast to the pot, bring to a boil, and cover. Place in the oven for 1 hour.

Step 7

Turn the heat down to 250°F (120°C) to keep the sauce at a gentle simmer. Continue to roast until the meat is fork-tender or the pot roast registers 160°F (71°C), about 1 1/2 hours, for a total of 2 1/2 hours in the oven.

Step 8

Transfer the roast to a cutting board. Remove the herb bundle and discard. Skim and discard as much fat as possible from the surface of the sauce.

Step 9

Transfer half the sauce and vegetables to a blender or a food processor fitted with the steel blade and puree until smooth.

Step 10

Pour the puree back into the pot, place on the stove top over low heat, and return the sauce to a simmer. Meanwhile, place 2 tablespoons flour and the butter in a small bowl and mash them together with a fork. Stir the butter mixture into the sauce and simmer, stirring constantly, until thickened, 1 to 2 minutes. Remove from the heat, taste, and adjust the seasonings accordingly.

Step 11

Remove the strings from the roast and slice the meat. Pile it onto a platter and serve it warm with the sauce spooned over it. (You may have some leftover sauce, which you can cover and refrigerate for up to 3 days. Rewarm it gently over low heat and, if desired, add a splash of red wine just before serving. It's delicious over pasta.)