1. Have your market trim pork of fat, then bone, roll, and tie the meat, saving the bones (or do this yourself). 2. Place meat in a 5-6 quart ovenproof pan on medium-high heat. Turn often until meat is well browned all over, about 10 minutes. Add stock, sage, and lemon juice; stir to scrape browned bits from pan. Cover very tightly and bake in a 325F. oven for 1 hour. 3. Add carrots and potatoes to meat. Cover and bake until vegetables are barely tender when pierced, about 20 minutes. Add turnips and parsnips; cover and bake until all vegetables are tender when pierced, about 40 minutes longer. 4. When vegetables are done, place cabbage in a 10-12" frying pan with 1/2" water. Bring water to boiling over high heat, cover, and simmer until cabbage is tender when pierced, about 10 minutes. 5. Transfer meat and vegetables to a large platter; keep warm. Skim fat from pan juices; bring juices to a boil over high heat. Add cornstar mixed with 1/3 cup water and bring to a second boil, stirring. Pour into a small pitcher. Slice meat and serve with vegetables; add gravy and salt and pepper to taste. *** RICH PORK STOCK *** 1. Place reserved pork bones in a 10x15" pan with onions and carrots. Roast in a 450F. oven, mixing occasionally, until bones are well browned, 40-50 minutes. 2. Add 1/2 cup water to pan; stir vigorously to free browned bits. Scrape mixture into a 5-6 quart pan. Add 1 quart water, celery, and thyme. Bring to a boil over high heat, then cover and simmer for 1 1/2 hours. 3. Uncover pan and boil over high heat until liquid is reduced to 2 1/2 cups, about 10 minutes. Pour mixture through a fine strainer into a bowl. Discard bones and vegetables. If stock is made ahead, cool, cover, and chill up to 2 days. Skim or lift off fat and discard.