Bring beef rump to room temperature 30 minutes before cooking. Sprinkle the rock salt all over the meat. Secure rump on skewers, add to a rotisserie grill, allowing the meat to turn. Otherwise, place it on the barbeque grill, over medium heat, with the fat side down.
Cook rump until a core temperature of 56°C for medium rare consistency. Tap skewer to knock off any extra salt. Transfer to a tray, cover loosely with foil to rest for half the cooking time.
Serve with chimichurri sauce, roasted bell peppers and a green salad.
