Prepare the Bread: Preheat your oven to 300°F (150°C). Spread the bread cubes on a baking sheet in a single layer. Toast in the oven for about 20–25 minutes, until the bread is dry but not browned. This helps the bread absorb the broth without becoming too mushy. Let it cool.
Cook the Vegetables: In a large skillet, melt the butter over medium heat. Add the onions and celery, and cook until softened, about 10–12 minutes. Add the garlic, rosemary, sage, and thyme, and cook for another 2–3 minutes, until fragrant.
Combine Ingredients: Place the toasted bread cubes in a large mixing bowl. Pour the vegetable mixture over the bread, along with fresh parsley. Season with salt and pepper.
Add Broth and Egg: Pour in 2 cups of broth and toss to combine. Add the beaten egg and mix well. Gradually add more broth as needed until the bread is moist but not soggy.
Bake the Stuffing: Transfer the stuffing to a buttered baking dish. Cover with foil and bake at 350°F (175°C) for 30 minutes. Remove the foil and bake for another 15–20 minutes, until the top is golden and slightly crispy.
Serve and Enjoy: Let the stuffing cool for a few minutes before serving.