Saute celery and onions in butter until tender. Toss with bread cubes. Blend eggs whites with 1 1/2 cups broth. Add seasonings. Pour over cubes and stir gently. Pour into a greased casserole dish. Bring 1 1/2 cups broth to a boil in small saucepan. Combine flour with remaining broth until smooth. Whisk into hot broth. Add seasonings. Cook for 2-3 minutes. pour over stuffing. Cover tightly. Bake at 350 degrees for 45 minutes. Serves 8 THM E category.