Prepare dressing; whisk together the oil, lemon juice, mustard and pepper. Shave cheese using vegetable peeler.
Prepare vegetables; de–seed and thinly slice cucumber, thinly slice apple and onion.
Place rocket, cucumber, apple and onion onto serving dish. Drizzle dressing over salad and top with shaved cheese.
Tip: Place dressing ingredients in a clean empty jar with a tight fitting lid and shake well to combine.