In 12-inch skillet, heat oil over medium-high heat. Cook ribs in two batches, fattiest side down first, on all sides 2 to 3 minutes per side, until browned. Transfer to plate; cool 15 minutes. Discard fat and pan drippings. Transfer ribs to labeled 1-gallon freezer bag. Pour 1/3 cup soy sauce over ribs and seal bag, pressing out as much air as possible. Lay flat and freeze up to 3 months.