To prepare lamb, sprinkle evenly wth 3/4 tsp salt and pepper. Place lamb on a broiler pan coated with cooking spray and bake at 425 for 20 minutes or until a thermometer reads 120 degrees in the thickest part of the meat. Place lamb on a cutting board; let stand at room temperature 10 minutes before slicing.
To prepare sauce, combine sambal oelek and next 4 ingredients (through garlic) with a mortar and pestle; grind into a fine paste. Slowly drizzle oil into sambal mixture, stirring until thoroughly combined. Serve sauce with lamb.
