Preheat the oven to 350°F (176°C).
Heat the large skillet or pan to medium-high, add butter. Allow the butter to almost fully melt.
Add celery and onion. Stir and cook for 2-3 minutes.
Add garlic and fresh herbs; mix well. Season with salt and pepper. Cook for 3-5 minutes or until fragrant.
Pour in 6 cups of broth. Bring it to a simmer.
Place the dried bread in a large pot/bowl. Pour the broth mixture over the bread in the pot/pan. Mix well. If the dressing looks/feels dry add another cup of broth (adjust to you liking).
Spray the two baking pans (9" x 13"x2") with cooking olive oil or butter.
Transfer the dressing mixture to the 2 baking pans.
Bake (uncovered) for 40-45 minutes or until golden and crispy on top.