1 (14- to 16-oz.) sourdough loaf, torn into 1-in. pieces (about 9 cups)
1/2 cup vegan butter, plus 1/4 cup melted vegan butter
8 oz. fresh shiitake mushrooms, stems removed, caps cut into 1/4-inch slices
10 oz. cremini mushrooms, sliced
1 medium onion, chopped
2 cloves garlic, finely chopped
2 tablespoons finely chopped fresh sage
1 tablespoon finely chopped fresh thyme
3/4 teaspoon salt
1/2 teaspoon freshly ground black pepper
1 cup dry white wine
5 oz. roasted, peeled chestnuts, roughly chopped
1/2 cup chopped toasted pecans
2 1/2 to 3 cup vegetable stock
Preheat oven to 350 degrees. Grease a 9-by-13-inch baking dish. Set aside.
Place bread pieces on a large, rimmed baking sheet and bake for 10 minutes. Stir and continue to bake for another 10 to 15 minutes, until the bread is crispy, but not browned. Remove from oven and set aside to cool.
Meanwhile, melt 1/2 cup vegan butter in a 12-inch nonstick skillet over high heat. Add shiitake and cremini mushrooms and cook, stirring frequently, for 10 minutes or until lightly browned. Add onion and garlic and cook, stirring, for about 3 minutes or until softened. Add wine, thyme, sage, salt and pepper and continue to cook, stirring, until most of the liquid has evaporated, about 1 to 2 minutes. Remove from heat.
In a large bowl, combine bread and 1/4 cup melted vegan butter and toss to coat. Add mushroom mixture, chestnuts and pecans to the bread. Drizzle 2 cups of vegetable broth over the top and gently toss to combine. Add a little more broth if the mixture is too dry.
Transfer to prepared dish and bake until top is browned and crisp, about 30 to 40 minutes. Let cool for 10 minutes and serve.