Preheat oven to 375°F (190°C). Spread bread cubes on a baking sheet and toast for 10-15 minutes until dry and lightly golden. Transfer to a large bowl.
In a large skillet, melt butter over medium heat. Add onion and celery; cook until softened, about 8 minutes. Add garlic, sage, thyme, rosemary, salt, and pepper; cook 1 minute more.
Pour the vegetable mixture over the bread cubes and toss to combine.
In a small bowl, whisk together broth and egg. Pour over bread mixture and stir gently until evenly moistened. Fold in parsley.
Transfer stuffing to a greased 9x13-inch baking dish. Cover with foil and bake for 25 minutes. Remove foil and bake for 15-20 minutes more until golden and crispy on top.
Let rest 5 minutes before serving.
Tips
For extra flavor, use homemade broth or add 1/2 cup dried cranberries or chopped apples.
Stuffing can be prepared a day ahead; refrigerate unbaked and add 10 minutes to baking time.
If using fresh herbs, triple the amounts of sage, thyme, and rosemary.