Scrape the meat, bones and vegetables into a stockpot. Set the roasting pan over high heat and add 1 cup of the water. Cook, scraping up the browned bits, until the pan is clean. Pour the pan juices into the stockpot along with the remaining 3 cups and 3 quarts of water and simmer over moderately high heat for 30 minutes, skimming occasionally. Reduce the heat to moderately low, cover partially and simmer until the stock is richly flavored and reduced to 2 quarts, about 4 hours. Season with salt.