Preheat the oven to 375°F (190°C).

In a small bowl, mix together olive oil, minced garlic, rosemary, thyme, salt, and pepper.

Rub the mixture all over the lamb roast, ensuring it's well coated.

Heat a roasting pan over medium-high heat and sear the lamb roast on all sides until browned, about 5-7 minutes.

Transfer the lamb roast to the oven and roast for about 1 hour and 15 minutes, or until the internal temperature reaches 135°F (57°C) for medium-rare.

Baste the roast with chicken broth every 30 minutes to keep it moist.

Remove the roast from the oven and let it rest for 15 minutes before slicing.