Ingredients:

• 2 tablespoons ground flaxseed
• 5 tablespoons room temperature water
• 6 tablespoons vegan margarine, divided, plus more for greasing the pan
• 2 tablespoons olive oil
• 1 pound mixed mushrooms, roughly chopped
• 1 cup finely chopped yellow onion
• 3 scallions, thinly sliced
• 1 cup chopped celery
• 2 cloves garlic, thinly sliced
• 1 tablespoon dried sage or 3 tablespoons fresh, chopped sage leaves
• 1 1/2 teaspoons dried thyme or 1 1/2 tablespoons fresh thyme leaves
• 4 cups vegetable stock
• 4 ounces toasted, finely chopped walnuts
• 1/2 cup fresh, finely chopped parsley, divided
• 2 1/2 pounds (40 ounces) stale sourdough bread, cubed or torn into bite-size pieces
• Salt and pepper, to taste