Prep The Bread: Cut the bread into even-sized cubes, about 1/2-inch. Let the bread cubes dry out overnight. Or, preheat the oven to 350°F, spread the bread cubes on a baking sheet, and toast them for about 10 minutes, until dry and lightly golden. From there, set them aside to cool.
Melt the butter in a skillet over medium heat on the stove. Then, add the finely diced onion, celery, and crushed garlic to the skillet. Sauté these ingredients until softened, about 5 minutes.
Add the dried bread cubes, sautéed ingredients, fresh or dried thyme, rosemary, sage, parsley, salt, and pepper to a large bowl. After that, pour the broth and whisked egg into the bowl, stirring gently until evenly combined.
Lightly spray a small 8x8 baking dish with oil. Then, transfer the stuffing to the baking dish. Cover the baking dish with foil and bake at 350°F for 20 minutes. Then, remove the foil and bake for an additional 20-25 minutes, until the top is golden and slightly crisp. Next, let the stuffing slightly cool, serve, and enjoy!