FOR THE MARINADE:
In a glass or stainless-steel pan large enough to hold the chops, combine the marinade ingredients. Add the lamb and coat on both sides. Marinate for at least 1 hour, turning the meat over after 30 minutes. Heat the grill or a broiler.
Remove the chops from the marinade. Grill or broil to the desired degree of doneness.
FOR THE SAUCE:
In a small saucepan over high heat, combine the wine, shallots, and garlic and boil briefly until the liquid is reduced to 1 tablespoon. Add the beef broth and simmer over low heat for 5 minutes. Strain out the shallots and the garlic. Return the broth to the saucepan. Whisk in the arrowroot and heat briefly until slightly thickened. Keep the sauce warm over low heat. Just before serving, whisk in the butter, if desired.
When the chops are finished, divide them among 4 dinner plates and spoon some of the sauce on each chop.
