Preheat oven to 375°F (190°C). Pat the lamb dry and make small cuts all over with a knife.
Rub with olive oil, salt, pepper, garlic, rosemary, and lemon juice.
Place in a roasting pan on a rack. Roast for about 20 minutes per pound.
Use a meat thermometer—135°F (57°C) for medium-rare, 145°F (63°C) for medium.
Rest 15 minutes before carving. Serve with roasted veggies or potatoes.
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