On a hot pan, sear the steak. Lower the heat to medium and add butter, thyme and garlic. Fry the steaks for 4 minutes on each side and baste with butter continuously. Remove from the pan and let the steaks rest for 10 minutes before cutting them into thin slices. In a bowl add rocket salad with slices of steak on top. Add halved tomatoes, caper berries and olives. Sprinkle pine nuts and finish with crumbled pieces of Castello Extra Mature Cheddar.
Make the vinaigrette in small jar by adding mustard, lemon juice, basil, salt and pepper. Put on the lid and shake well. If you bring the salad with you on a picnic, simply pour the vinaigrette over the salad just before serving it.