Tear or cut your sourdough bread into cubes. Spread the cubes on a baking sheet and toast them in a 300°F oven for 15-20 minutes, or until they’re slightly dry but not too crispy. Set aside.
In a large skillet, melt butter over medium heat. Add the chopped onion, celery, and garlic. Sauté for about 5-7 minutes until the vegetables are soft and translucent.
In a large mixing bowl, combine the toasted sourdough cubes, sautéed vegetables, sage, thyme, salt, and pepper. Toss everything together to mix evenly.
Gradually pour in the broth while stirring to coat the bread cubes evenly. If you’re using an egg, beat it and stir it into the mixture for a bit more binding. Adjust the liquid amount if necessary, depending on how moist you like your stuffing.
Transfer the stuffing mixture to a greased 9x13-inch baking dish. Cover with foil and bake at 350°F for 30 minutes. After 30 minutes, remove the foil and bake for an additional 15-20 minutes until the top is golden and crispy.
Garnish with fresh herbs, if desired, and serve alongside your holiday meal or family dinner.