Preheat the oven to 400°F and spray a 13 X 9 X 2-inch baking dish with nonstick cooking spray.
In a large skillet, add ½ cup unsalted butter and melt it over medium heat. Add the ½ cup diced onions and ½ cup diced celery. Cook until soft, about 6-7 minutes.
Add 1 (10-ounce) box stuffing bread crumbs, 1 ½ cups chicken broth, and cooked veggies, and stir to combine.
Transfer the stuffing mixture to the prepared dish. Cover with foil and bake for 20-25 minutes. Remove the foil and bake for an additional 10-15 minutes or until golden brown.
Notes
Storage, Reheating & Make Ahead Instructions
Storage: Once cooled, store leftovers in an airtight container in the refrigerator for up to 3 days.
Reheating: Microwave for about 1 minute, or until warmed through. Add a splash of chicken broth before reheating if the stuffing seems dry.
Make Ahead: Assemble the stuffing as directed, then cover tightly with plastic wrap and refrigerate for up to 2 days. Bring to room temperature before baking as directed.