Method 
Heat a BBQ grill plate over medium-high heat. Lightly season the steaks with sea salt and drizzle with olive oil. For medium rare, grill each steak for 4 minutes each side, 8 minutes each side for medium and 16 minutes each side for well-done.
To test if your steak is cooked to your liking, press the centre with the back of the tongs. The steak will feel soft if it's rare, slightly firmer and springy when it's medium and very firm when it's well-done.
Remove the steaks and place on a plate to rest for half of its cooking time. Combine ¼ cup olive oil in a small bowl and stir through thyme leaves. Brush onto steak while resting and season with sea salt.
Serve with mustard and watercress or rocket.
