Heat 2 tablespoons butter in a medium skillet over medium heat. Add the dried pears, chestnuts, 2 chopped shallots, the minced garlic, 2 teaspoons rosemary and 1 teaspoon thyme; season with salt and pepper. Cook, stirring, until the shallots soften, 5 to 6 minutes. Add the wine and simmer until dry, 1 to 2 minutes. Add the chicken broth and simmer until dry, 5 to 6 minutes. Let cool.
Place the turkey legs skin-side down (they will be rectangular). Season with salt and pepper. Divide the pear filling between the legs, forming each into a log along one long side. Fold the meat over the filling and roll up. Tie each roulade with kitchen twine in 1 1/2-inch intervals, then tie a long piece of twine lengthwise to secure. Refrigerate until ready to cook.
Season the turkey breast all over with salt and pepper; let sit at room temperature 1 hour. Position a rack in the lower third of the oven and preheat to 350 degrees F.
Meanwhile, make the glaze: Bring the pear juice, honey, 1 teaspoon rosemary, the remaining 1/2 teaspoon thyme, the smashed garlic clove and the vinegar to a boil in a small saucepan. Reduce the heat and simmer until thickened, 12 to 18 minutes. Discard the garlic and season the glaze with salt and pepper. Let cool.
Mix the remaining 4 tablespoons butter with the remaining 1 teaspoon rosemary. Pat the turkey breast dry with paper towels and rub the butter all over the skin. Arrange the halved shallots, carrots and celery in the middle of a large roasting pan. Place the turkey breast on top of the vegetables. Roast 1 hour.
Meanwhile, heat the vegetable oil in a large skillet over medium-high heat. Pat the roulades dry and season all over with salt and pepper. Brown in the skillet on all sides, 10 to 12 minutes.
Baste the turkey breast with most of the pear glaze. Add the roulades to the roasting pan. Roast until a thermometer inserted into the roulades registers 170 degrees F, 40 to 50 minutes, and the breast registers 160 degrees F, 45 to 60 minutes (tent with foil if the glaze gets too dark). Remove each piece to a cutting board as it's done. Brush the breast with the remaining pear glaze and let rest at least 30 minutes before slicing. Use the pan drippings for gravy.
Fill, roll and tie the roulades (steps 1 and 2) and make the glaze (step 4) up to 1 day ahead; refrigerate. Reheat the glaze in the microwave in 5- to 10-second intervals.