Prepare the bread: Dice the loaf of French bread into cubes and let it sit uncovered overnight to dry.
Cook the sausage: In a large skillet, cook the sausage over medium heat until browned. Transfer to a plate and set aside.
Sauté the aromatics: In the same skillet, melt butter and add diced onion and celery. Sauté until softened and fragrant, about 5–7 minutes.
Add the herbs: Stir in rosemary, sage, and thyme. Cook for another 1–2 minutes to release their flavor.
Combine everything: In a large bowl, add the dried bread cubes, cooked sausage, and sautéed vegetables. Pour in the chicken broth and toss gently until evenly moistened.
Season: Add salt, pepper, and parsley, mixing to combine. Adjust moisture if needed with a bit more broth.
Transfer to slow cooker: Lightly grease the slow cooker insert and pour in the stuffing mixture, pressing down lightly.
Cook: Cover and cook on LOW for 3–4 hours or until heated through and the top is slightly crisp.
Crisp up (optional): For extra crunch, uncover during the last 30 minutes or transfer to a baking dish and broil for a few minutes before serving.
Serve: Garnish with fresh parsley and serve warm alongside your favorite main dish.