Season chops w/ salt and pepper. Heat oil in lg skillet over med-high heat. Brown chops on both sides, remove chops from skillet, place on a plate.
Place butter in skillet to melt, stir in garlic, cook 1 min. Pour in the vinegar, scraping the bits from bottom of pan. Add cider and mustard. Bring to a boil. Cook, stirring until thickened. Stir in rosemary and a pinch of red pepper flakes. Put chops back into pan and cook about 5 mins.