In nonstick 12-inch skillet over medium heat, in 2 teaspoons hot oil, cook onion until tender. Remove onion to small bowl.
If using rosemary in place of the thyme, at this point, press one small spring onto one side of each chop. In same skillet over medium-high heat, cook pork chops 5 minutes, sprinkling with 1/2 teaspoon salt. Turn pork chops; sprinkle with thyme if using in place of rosemary, pepper and 1/2 teaspoon salt. Cook 3 to 5 minutes longer or until pork just loses its pink color throughout. Remove pork chops to four warm dinner plates; keep warm.
Cut unpeeled apple into 1/4-inch-thick slices. In same skillet in remaining 2 teaspoons hot oil, brown apple slices; sprinkle with sugar. Remove to plates with chops.
In cup, mix apple juice and cornstarch. Stir apple-juice mixture and onions into skillet, stirring constantly until mixture boils. Boil 1 minute. Pour mixture over pork chops and apple slices.
Read more: Boneless Pork Chops with Sauteed Apples - Good Housekeeping.