Cut the celery into pieces one inch long. Boil in salted water until tender; drain and mix with a white sauce.
Cut heads of celery into pieces six inches long, leaving them attached to the root; remove the coarse branches, and trim the roots neatly. Parboil it for five minutes. Make a brown roux, using two tablespoonfuls each of butter and flour, one teaspoonful of salt, and one quarter teaspoonful of pepper, and dash of nutmeg. Add two cupfuls of stock when the roux is well browned; and in this, place the bunches of celery; cover and cook very slowly for twenty-five minutes. Remove the celery, and place it evenly on a dish. Strain the gravy; pour it around or over the celery.
Cut carrots and turnips into dice one quarter of an inch square, or with a small potato scoop cut them into balls. Boil them separately in salted water; drain and mix them carefully together. Stir lightly into them enough white sauce to moisten them well.