Place a rack in the lower third of the oven and preheat it to 450ºF. In a small bowl, combine finely chopped garlic, chopped fresh rosemary, fresh thyme leaves, and 1 tablespoon of extra-virgin olive oil. Season the mixture generously with kosher salt and freshly ground black pepper. Rub this aromatic mixture all over the boneless lamb shoulder roast to infuse it with rich herbs and garlic flavors.

In a 13'' x 9'' baking dish, toss the baby potatoes with the remaining 2 tablespoons of olive oil. Season the potatoes with kosher salt and freshly ground black pepper to taste. Arrange the seasoned lamb shoulder on top of the potatoes in the baking dish, allowing the flavors to mingle during roasting.

Place the baking dish in the preheated oven and roast until an instant-read thermometer inserted into the thickest part of the lamb registers 145ºF, which will take about 1 hour. This ensures the lamb is perfectly cooked to medium-rare, maintaining its juiciness and tenderness.

Remove the lamb from the oven and let it rest for 15 minutes to allow the juices to redistribute. After resting, remove the butcher’s twine before slicing the lamb. Serve the sliced lamb alongside the roasted baby potatoes for a hearty and flavorful meal.