Preheat the oven to 350°F and lightly grease a 9×13-inch casserole dish.
In a large skillet, melt the butter over medium heat. Add the onion, celery, and garlic, and cook for 6 to 8 minutes or until softened. Stir in the sage, thyme, rosemary, salt, and pepper.
½ cup unsalted butter, 1 medium onion, 2 celery stalks, 2 to 3 garlic cloves, 2 teaspoons dried sage, 1 teaspoon dried thyme, 1 teaspoon dried rosemary, 1 teaspoon salt, ¼ teaspoon black pepper
In a separate bowl, whisk together 2 cups of chicken broth and the eggs until well combined.
2 to 2 ½ cups low-sodium chicken broth, 2 large eggs
Add the cubed bread to a large mixing bowl, then pour in the sautéed vegetables. Stir to combine, then pour in the egg and broth mixture. Gently toss until the bread is evenly moistened, adding the remaining ½ cup of broth only if needed.
1 loaf of day-old bread
Transfer the mixture to the prepared baking dish, cover with foil, and bake for 30 minutes. Remove the foil and bake for another 10 to 15 minutes, or until the top is golden brown and slightly crisp.