Lamb Chops with Cherry Balsamic Sauce and Mint

Stir fresh cherries together with sugar and macerate while browning chops. If using frozen cherries, stir with any juices and sugar and thaw, about 1 1/2 hours. Pat lamb dry and sprinkle with salt and pepper. Heat 1 tablespoon oil in a 12-inch nonstick skillet over moderately high heat until hot but not smoking, then sauté 4 chops, turning over once, about 6 minutes total for medium-rare. Transfer to a plate and loosely cover with foil. Cook and transfer remaining 4 chops in same manner. Pour off fat from skillet and add remaining tablespoon oil. Heat until hot but not smoking, then sauté shallot, stirring, until golden brown, about 3 minutes. Add cherries with juices, broth, and vinegar and bring to a boil, stirring occasionally and scraping up brown bits, then reduce heat and simmer 3 minutes. Add salt and pepper to taste, then add butter and 2 tablespoons mint, stirring just until butter is melted. Spoon sauce over chops and sprinkle with remaining 2 tablespoons mint.