1. If using wooden skewers, pre-soak them in cold water for about one hour. This will stop the skewers from burning when in contact with heat
2. In a mortar and pestle, add whole peppercorns and rock salt. Grind until you have a fine ground. Add cumin and garlic and pound until well combined and garlic resembles a paste. Add olive oil and mix through. Set aside.
3. Thread beef cubes onto skewers, alternating with red and green capsicum. You should be able to fit four cubes of beef and three squares of capsicum onto each skewer.
4. Place beef kebabs on a tray and using a pastry brush, marinade onto all sides of the beef kebab. Cover tray and refrigerate for one hour. If short on time, refrigerating isn’t essential.
5. Preheat a barbecue or grill on high until hot. Reduce the heat to medium. Cook the beef kebabs for four minutes on one side. Turn and cook for a further two minutes for medium rare. Leave to rest for six minutes before serving.
6. Serve with your choice of salad and a side of hummus