1.Cook potatoes in a large pan of simmering, salted water for 10-12 minutes, until tender. Drain.
2.Meanwhile, combine garlic, thyme and rosemary and rub into lamb. Heat oil in a frying pan on high. Cook lamb, turning, for 4-6 minutes for medium-rare, or until cooked to your liking. Cover loosely with foil and rest for 5 minute.
3.Place tomato, orange, potatoes and lamb in a bowl and toss to combine. Arrange lamb salad and rocket in serving bowls. Whisk together dressing ingredients and pour over salad. Top with pine nuts and pecorino to serve.