Mix together the crushed peppercorns and the crushed dried chillies, if using, on a plate. Press one side of each steak into the mixture to create a light crust.
Heat the oil in a large frying pan until very hot, then add the steaks, crust downwards. Sear on both sides until golden brown. Turn the steaks peppercorn crust upwards.
Mix the creamed horseradish and Roquefort together with the chopped parsley and spoon on to the top of each steak.
Cook the steaks for 2 more minutes for medium or 4–5 minutes for well-done meat. Then place briefly under a preheated hot grill to brown the Roquefort crust slightly. Garnish with extra parsley and serve immediately with root vegetables, such as sweet potatoes and beetroot.