Heat your smoker to 350°F.
Place the bread cubes in a 9"x12" baking pan.
Heat butter in a skillet over medium heat, add the celery and onions, season with salt and pepper, and cook till softened, about 10 minutes.
Remove from the skillet and spread on top of the breadcrumbs.
In the same skillet cook the breakfast sausage, breaking up it up with a wooden spoon as you go, until browned.
Once cooked place aside in a bowl making sure to drain any excess oil.
In the same skillet, add the chicken stock, roasted garlic, unsalted butter, parsley, sage, and thyme. Stir that together and scrape the bottom of the skillet to release the bits of sausage stuck there. Bring to a simmer for a few minutes.
Add the cooked sausage and chicken stock mixture to the baking pan with the breadcrumbs and stir gently to combine.
Cover baking pan with foil and place in smoker for 30 minutes.
After 30 minutes remove the foil and cook for another 10 minutes. Serve warm.