Melt shortening in a large skillet over medium heat; add pork chops, and brown on both sides. Remove chops from skillet, and drain on paper towels; drain off pan drippings.
Sauté green pepper, onion, and celery in 1/4 cup butter in a medium saucepan . Remove from heat; add corn, breadcrumbs, egg, salt, and pepper, stirring until well blended. Set vegetable mixture aside.
Melt remaining butter in a heavy saucepan over low heat; add flour , stirring until smooth. Cook 1 minute, stirring constantly. Gradually add milk; cook over medium heat, stirring constantly, until thickened and bubbly.
Arrange pork chops in a lightly greased 13- x 9- x 2-inch baking dish . Spoon vegetable mixture over pork chops. Pour white sauce evenly over vegetable mixture. Bake, uncovered, at 300° for 45 minutes or until pork chops are tender. Serve immediately.