1 roast, bone in, about 6 pounds
2 teaspoons salt
1 can (20 ounces) sliced pineapple in syrup
1/4 cup sugar
1 tablespoon cornstarch
1 egg yolk, lightly beaten
2 tablespoons margarine
Preheat oven to 325. Rub the roast with salt and pepper. Place the roast, fat side up, on a rack in shallow roasting pan. Roast, uncovered for about 15 to 20 minutes per pound, until meat thermometer registers an internal temperature of 140 to 150. Meanwhile, drain pineapple, reserving syrup. Add water to syrup to make 1 cup of liquid. Combine sugar, cornstarch, and salt in a small saucepan; add pineapple liquid. Cook over medium-low heat, stirring constantly, until thickened. Stir a small amount of the hot mixture into the lightly beaten egg yolk; return egg to the hot mixture in saucepan. Continue cooking and stirring for 1 minute. Stir in margarine. Arrange 3 or 4 pineapple slices on the roast and spoon on some of the sauce to glaze; roast 10 minutes longer. Cut remaining pineapple into chunks and add to sauce. Serve with roast.