Bread Stuffing 101

Name: Bread Stuffing 101
Ingredients: 8 tablespoons (1 stick) unsalted butter; 1 large onion, chopped; 3 medium celery ribs with leaves, chopped; 15-ounce bag cubed seasoned stuffing or 1 pound firm white sandwich bread, cut into 1/2-inch cubes (10 cups) and dried overnight or in the oven; 1/4 cup chopped fresh parsley; 3 cups homemade turkey stock or canned reduced-sodium chicken broth; 2 teaspoons poultry seasoning, preferably homemade (recipe follows), optional; Salt and freshly milled black pepper