Preheat the oven to 350°F.
In a large skillet, heat 1 tablespoon of the oil. Sauté the onion and celery until tender, about 5-7 minutes.
Use the remaining oil to grease a medium casserole dish and pour the sautéed vegetables into the dish.
Add all the remaining ingredients and toss well, making sure all of the bread cubes are soaked in the vegetable broth. Bake for 45 minutes.