You will need a large kettle. Cover corned beef with cold water; bring to simmering; cook at this temperature for 3.5 to 4 hours or until the meat is tender. At the end of 3.5 hours, add pared potatoes, carrots, parsnips, turnips and peeled whole onions to meat in the kettle. Lay cabbage wedges over top of vegetables and meat. Cover; cook for about 25 minutes or until vegetables are tender. Cook beets separately, if fresh, until tender. Depending on size of beets, beets take longer to cook than some vegetables. If canned, reheat to boiling. When all is cooked, remove meat and vegetables to a large platter; keep warm while the dumplings cook in the kettle juices. FOR THE DUMPLINGS: This needs to be a stiff moist batter. Mix together and sift the flour, salt, baking powder and pepper. Combine egg and milk with melted butter; add to sifted dry ingredients. Have "pot likker" (liquid in which dinner was cooked) boiling. Spoon batter by tablespoonfuls into boiling liquid. Cook, uncovered, until liquid boils again; cover kettle tightly and cook for 20 minutes. Do not lift cover during cooking.