Prepare the cornbread: If using homemade cornbread, bake it according to recipe instructions and let it cool. Cube it into small pieces. If using store-bought cornbread, cube it into pieces.

1. Cook the vegetables: Heat olive oil (or butter) in a large skillet over medium heat. Add onion, celery, and garlic. Sauté for 5-7 minutes, until the vegetables are soft and fragrant. Add sage, thyme, salt, and pepper, and cook for an additional minute.
2. Combine the ingredients: In a large mixing bowl, add cubed cornbread and sautéed vegetable mixture. Toss gently to combine.
3. Add the liquid: In a small bowl, whisk together broth and beaten egg. Pour the mixture over the cornbread and vegetables. Stir to combine. If the stuffing is too dry, add more broth, one tablespoon at a time.
4. Bake the stuffing: Preheat the oven to 375°F (190°C). Transfer the stuffing to a greased 9×13-inch baking dish. Cover with foil and bake for 25 minutes. Remove the foil and bake for another 10-15 minutes until the top is golden brown and crispy.
5. Serve: Garnish with fresh parsley (if using) and serve immediately.