- 3/4 cup (1 1/2 sticks) unsalted butter, cut into pieces, divided, plus more
- 10 cups coarsely torn baguette, dried out overnight
- 1/4 cup pine nuts
- 3 tablespoons olive oil
- 4 ounces pancetta, cut into 1/4″ pieces
- 2 large leeks, white and pale-green parts only, thinly sliced
- 4 celery stalks, chopped
- Kosher salt, freshly ground pepper
- 1/4 cup Cognac
- 2 large eggs
- 3 cups chicken stock or low-sodium chicken broth, divided
- 1 cup coarsely chopped canned smoked oysters
- 2 tablespoons chopped fresh thyme
- 2 tablespoons finely chopped fresh sage
- 2 teaspoons finely grated lemon zest
- 1/2 lemon, thinly sliced, seeds removed
- Preheat oven to 350°. Butter a shallow 3-quart baking dish and a sheet of foil. Place bread in a very large bowl.
- Toast nuts on a rimmed baking sheet, tossing once, until golden brown, 6-8 minutes. Let cool; add to bowl with bread.
- Meanwhile, heat oil in a large skillet over medium-high. Cook pancetta, stirring often, until browned and crisp, 5.8 minutes. Transfer to bowl with a slotted spoon.
- Add leeks and celery to skillet, season with salt and pepper, and cook, stirring often, until leeks are golden brown and soft, 10.15 minutes. Transfer to bowl.
- Reduce heat, add Cognac to skillet (take care, as it can ignite), and cook, scraping up any browned bits, until almost all evaporated, about 1 minute. Add 1/2 cup butter; cook, stirring, until melted. Drizzle over bread mixture.
- Whisk eggs and 2 cups stock in a medium bowl; pour over bread mixture. Add oysters, thyme, sage, and lemon zest, season with salt and pepper, and toss, adding more stock 1/4-cupful at a time as needed (you may not use it all), until combined and bread is hydrated. Transfer to prepared dish and dot with remaining 1/4 cup butter. Top with lemon slices.
- Cover with buttered foil; bake until a paring knife inserted into the center comes out hot, 30-35 minutes. Increase oven temperature to 450°. Uncover and bake until top is golden brown and crisp, 20-25 minutes. Let sit 10 minutes before serving.
- Do ahead: Stuffing can be assembled 1 day ahead. Cover and chill.