In large skillet saute mushrooms, celery and onion in butter until mushrooms are tender. Toss with bread cubes, poultry seasoning, salt and pepper. Makes about 9 cups of stuffing, enough for a 10-12 lb. turkey. You may add chicken or turkey broth if you feel it is too dry, but I usually never have to do this.
Note: Stuffing can be baked in greased covered baking dish or casserole in 325 degree oven 45-60 minutes or until heated through. For drier, crispier stuffing, uncover last 15 minutes.