Put the mutton chops (cut from near the shoulder) in a shallow pan which has a tight cover. Pour on boiling water to the depth of one inch. Cover and simmer one hour. Add more water as it boils away, using only enough to keep the meat from burning. Add turnips, onions, and carrots. When the meat, turnips, and onions are nearly tender, add potatoes, which have been first parboiled. Add 1 teaspoon salt and a little pepper. Remove the vegetables without breaking them. Let the water boil nearly away, leaving enough for gravy. Remove the fat, thicken the gravy with flour. Add salt and tomato catsup to taste. Pour it over the meat.