Preparation Preheat oven to 350°F with racks in upper and lower thirds. Bake bread cubes in a large 4-sided sheet pan in upper third of oven until dried slightly, about 15 minutes. (Alternatively, leave out to dry at room temperature 8 to 24 hours.) Increase oven temperature to 450°F. Meanwhile, wash leeks. Melt butter in a 12-inch heavy skillet over medium heat, then cook leeks and celery, covered, stirring occasionally, until softened, about 10 minutes. Add thyme, apples, 1 teaspoon salt, and 1/2 teaspoon pepper and cook, covered, stirring occasionally, until apples are just tender, about 5 minutes. Transfer to a bowl and toss with bread, chestnuts, cream, parsley, 1/2 teaspoon salt, and 1/4 teaspoon pepper. Spread in a 2 1/2-to 3-quart shallow baking dish. Bake, uncovered, in lower third of oven until heated through and top is golden, about 30 minutes. Cooks' note:Stuffing can be assembled (but not baked) 1 day ahead and chilled (covered once cool). Bring to room temperature before baking.
Preparation Preheat oven to 350°F with racks in upper and lower thirds. Bake bread cubes in a large 4-sided sheet pan in upper third of oven until dried slightly, about 15 minutes. (Alternatively, leave out to dry at room temperature 8 to 24 hours.) Increase oven temperature to 450°F. Meanwhile, wash leeks. Melt butter in a 12-inch heavy skillet over medium heat, then cook leeks and celery, covered, stirring occasionally, until softened, about 10 minutes. Add thyme, apples, 1 teaspoon salt, and 1/2 teaspoon pepper and cook, covered, stirring occasionally, until apples are just tender, about 5 minutes. Transfer to a bowl and toss with bread, chestnuts, cream, parsley, 1/2 teaspoon salt, and 1/4 teaspoon pepper. Spread in a 2 1/2-to 3-quart shallow baking dish. Bake, uncovered, in lower third of oven until heated through and top is golden, about 30 minutes. Cooks' note:Stuffing can be assembled (but not baked) 1 day ahead and chilled (covered once cool). Bring to room temperature before baking.