Ingredients:
110 g unsalted butter, divided, plus more for dish and top
1 onion, finely chopped
1 leek (white and pale-green parts only), halved lengthwise, thinly sliced
3 tablespoons thyme leaves
600 g mushrooms, cleaned, trimmed, and thinly sliced
120 ml dry white wine
600 ml chicken broth
12 cups bread
3 large eggs, lightly beaten
Salt and pepper
Preparation:
Preheat oven to 190 degrees.
Brush a baking dish with butter.
Melt 2 tablespoons butter in a large sauté pan over medium heat. Add onion, leek, and 1/2 teaspoon salt, and cook, stirring occasionally, until softened, 7 to 8 minutes. Stir in thyme, and transfer to a plate.
Return the pan to the stove, raise heat to medium-high, and melt 2 tablespoons butter. Sauté half the mushrooms with 1/2 teaspoon salt, stirring occasionally, until golden brown, 3 to 4 minutes. Transfer to plate with onion and leeks. Sauté remaining mushrooms in same manner, and transfer to plate.
Return the pan to the stove over medium-high heat. Add wine, bring to a boil, and cook until reduced by half. Add broth and bring to a simmer.
Place the bread in a large bowl. Pour broth mixture over bread and toss until evenly absorbed. Gently stir in mushrooms, onion and leeks, and eggs, season with pepper.
Transfer dressing to baking dish. Cover, and bake 30 minutes. Uncover dish, dot with remaining 2 tablespoons butter, and bake until top is golden brown and crisp, 30 to 35 minutes. Let cool 30 minutes before serving.