Preheat oven to 375 degree F and arrange racks in upper and lower thirds of oven. Divide bread between 2 baking sheets, spreading out in a single layer. Bake, stirring occasionally, until golden and crisp, about 15 minutes. Transfer to a large bowl, reserving 1 baking sheet.

Preheat oven to 425 degree F. Toss together mushrooms and oil on reserved baking sheet; season with salt and pepper. Roast, stirring occasionally, until golden brown, about 20 minutes. Add to bowl with bread.

Cook bacon in a large nonstick skillet over moderate heat, turning, until crisp, about 6 minutes. Transfer to paper towels to drain, reserving fat and skillet; coarsely crumble bacon. Add three-quarters of bacon to bowl; reserve remaining bacon to garnish. Pour all but 1 tablespoon bacon fat into a heatproof cup and reserve.

Add butter, celery, and onion to reserved skillet; season with salt and pepper. Cook over moderately high heat, stirring, until tender, about 4 minutes. Add to bowl and reserve skillet. Add 1 tablespoon reserved bacon fat and the chestnuts to skillet. Cook over moderately high heat, stirring, until golden brown, about 3 minutes. Add to bowl along with apricots, herbs, and 1 cup stock; toss to combine. Let cool.

Set aside 8 cups stuffing for turkey. Transfer remaining stuffing to a 4-quart baking dish and drizzle with remaining 1 cup stock. Cover with aluminum foil and bake at 425 degree F 15 minutes. Remove foil and bake until top is crisp and golden brown, about 15 minutes more. Garnish with reserved bacon and serve warm. Makes 8 servings.