Shift the oven rack to the top level. Preheat the oven to broil for at least 10 minutes. (read this first
if you seldom cook with the broiler). Lightly oil a rimmed sheet pan and arrange the lamb and the cauliflower evenly around it. Brush any remaining marinade over the cauliflower to get it good and coated (this will also help it to roast and not burn).