Cut the sourdough into thick slices, then cube them into ½–1-inch pieces.
1 loaf sourdough bread
Spread the cubes evenly on a baking sheet and bake at 300°F (150°C) for about 30 minutes, tossing occasionally, until the bread is completely dry and crisp. Let cool.
Increase oven temperature to 375°F (190°C).
In a large skillet, melt the butter over medium-low heat. Add the onion and celery, and sauté for 10–12 minutes until soft and fragrant. Add the garlic and cook for another 1 minute.
6 tablespoons unsalted butter, 1 cup onion, 3–4 celery stalks, 2 cloves garlic
In a large mixing bowl, whisk together the broth and eggs. Add the dried bread cubes and toss to coat evenly.
2½–3 cups chicken or vegetable broth, 2 large eggs
Stir in the sautéed vegetables, herbs, salt, and pepper. Mix until the bread is evenly moistened—add more broth if it feels too dry. Transfer the mixture to a greased baking dish and cover with foil.
1 teaspoon salt, 2 teaspoons fresh thyme leaves, 2 teaspoons fresh sage, 2 teaspoons fresh rosemary, ½ teaspoon black pepper
Bake for 20 minutes, then uncover and bake for an additional 10–15 minutes until the top is golden and slightly crisp.
Garnish with a little extra parsley before serving warm.
½ cup fresh parsley