1. Salt the steak and sprinkle with black pepper.
2. Make a paste with equal amount of cayenne and mustard powder (for example, two tablespoons each).
3. At this point you can let it sit for a while in the fridge to develop flavor. If you don’t have time, you can grill it right away. Grill until steak is done, depending on the thickness of the steak and your desired doneness.