1.In a large mortar and pestle, grind peppercorns, chilli, salt and garlic to a smooth paste. Add chopped herbs and continue to pound to a coarse paste. Stir in vinegar and olive oil.
2.Brush steaks lightly with some extra olive oil, season with salt and pepper. Heat a grill pan or barbecue hot plate until very hot. Cook steaks, 4-5 minutes, before turning over.
3.Dollop a large spoonful of chimichurri onto the cooked side of the steak while the second side cooks for a further 4-5 minutes, or until cooked as desired.
4.Transfer steaks to a serving plate, stand for 5 minutes before serving with remaining chimichurri. Serve with boiled new potatoes and a crisp green salad or steamed beans, if desired.