Combine olive oil and next 3 ingredients in a large shallow dish or large heavy-duty zip-top plastic bag; add lamb chops, turning to coat. Cover or seal, and chill 2 hours.
Remove lamb chops from marinade, discarding marinade. Sprinkle evenly with salt and pepper. Place on a lightly greased aluminum foil-lined rack in a broiler pan.
Broil 3 inches from heat 5 minutes on each side or to desired degree of doneness. Top each lamb chop with a slice of Southwestern Butter; broil 30 more seconds. Serve immediately. Garnish, if desired.
*12 loin chops may be substituted for rib chops. Broil 3 or more minutes on each side or to desiered degree of doneness.
