Heat a large skillet over medium-high heat. Cook and stir sausage in the hot skillet until it is browned and crumbly, about 5 to 7 minutes. Use a slotted spoon to transfer the browned sausage to a large bowl.
In the same skillet, sauté garlic, celery, and onions until onion is tender; do not brown. Stir in 1/3 of the bread cubes. Transfer mixture to the large bowl with sausage. Add remaining bread cubes, herbs, and stock. Mix everything together well.
To bake stuffing: Preheat the oven to 350 degrees F (175 degrees C) and grease a 9x13 casserole dish with a little butter or cooking spray. Place stuffing mixture in the prepared baking dish and cover. Bake in the preheated oven until golden brown and crisp on top, about 25 minutes, basting occasionally with melted butter or turkey drippings.