1. Lay the slices of beef out on a work surface and pound gently to flatten slightly. Season with salt and pepper. In a mixing bowl, combine the pancetta, mashed garlic, parsley, celery, nutmeg, 1 teaspoon salt, and ½ teaspoon pepper. Mix with your hands to blend well. Divide the stuffing evenly among the beef slices. Roll each slice up over the filling at the wider end, fold in the sides, roll up, and secure with white kitchen string or toothpicks.

2. Place the dried cèpes in a small bowl and cover with 1 cup hot water; let stand for 30 minutes to soften. Remove the cèpes from the soaking liquid, squeezing the mushrooms to release the liquid into the bowl. Reserve the liquid. Chop the cèpes.

3. Heat the olive oil in the cazuela set over medium-low heat. Add the onion and carrot and cook until golden, about 10 minutes. Add the meat rolls and sauté slowly, turning, until browned all over, 20 minutes. Add the white wine, herb bouquet, garlic halves, tomato paste, cépes, reserved mushroom-soaking liquid, and stock. Raise the heat to medium and bring to a simmer. Cover with a sheet of parchment and a lid. Reduce the heat to low and simmer for about 2 hours, turning the beef rolls once after an hour. Transfer the beef rolls to a side dish and cover with foil. Drain the cooking juices, pressing down on all the vegetables and any pits of pancetta that may have fallen out. Let the beef rolls and sauce cool separately; then cover and refrigerate. (The recipe can be made to this point up to a day in advance.)

4. About 1 ½ hours before serving, completely degrease the sauce. Cut away the strings from the beef rolls. Return the beef rolls and the sauce to the cazuela. Cook, uncovered, over medium low heat for 1 hour, turning the beef rolls in the sauce from time to time. Stie in the vinegar and capers and simmer for a few minutes longer. Correct the seasoning with salt and pepper. Garnish with the chopped parsley and thyme, garlic, and orange zest and serve at once.