Brush the lamb all over with the curry paste. Cover and marinate at room temperature 20 minutes. While this occurs, combine the yogurt, lime juice, mint and salt in a bowl; cover and store in the fridge until the lamb is ready. Grill the lamb, lightly oiling the grill first if prone to sticking, 3-4 minutes per side, or until the desired doneness is achieved. Serve the lamb with the yogurt alongside for dipping.
Note: Curry paste, mild, medium or hot, is available in the Asian foods aisle.