Place lamb in a bowl. Mix all other ingredients together except salt, olive oil, stock and butter. Massage the lamb and marinate at room temperature for 15-30 minutes.
Heat pan over medium high heat. Add olive oil and butter. When it just starts to smoke a little, sear lamb for 3 to 4 minutes on each side for medium doneness. Baste continuously with pan oil and butter when searing. Set lamb aside and drain oil.
Deglaze pan with chicken stock to make pan jus. Pour jus over lamb when serving.