Step 1: Prepare the Lamb

• Preheat your oven to 325°F (160°C). This lower temperature allows for slow, even roasting, which is key to achieving tender and juicy lamb. Make sure your oven is properly preheated before placing the lamb inside.
• Remove the lamb from the refrigerator at least 1 hour before cooking. This allows the lamb to come to room temperature, which promotes more even cooking. If the lamb is too cold when it goes into the oven, the outside may cook faster than the inside, resulting in uneven doneness.
• Pat the leg of lamb dry with paper towels. Removing excess moisture from the surface of the lamb is crucial for achieving a beautifully browned and crispy crust. A dry surface will allow the olive oil and herb rub to adhere better and promote Maillard reaction, the browning process that creates delicious flavors.
• Trim excess fat from the leg of lamb, if desired. While some fat is desirable for flavor and moisture, excessive fat can render out and become greasy. Trim any thick layers of fat, leaving a thin layer for flavor. You can also score the fat in a crosshatch pattern to help it render evenly and create crispy edges. Be careful not to cut into the meat.

Step 2: Make the Herb and Garlic Rub

• In a small bowl, combine the chopped fresh rosemary, chopped fresh thyme, minced garlic, olive oil, lemon juice, salt, and black pepper (and red pepper flakes, if using). This is your flavor powerhouse! Ensure all the ingredients are well combined to create a homogenous rub. The olive oil will bind the dry ingredients together and create a paste-like consistency.
• Mix all ingredients thoroughly until well combined. Use a spoon or fork to mix everything together until the herbs are evenly distributed and coated in the olive oil and lemon juice mixture. The rub should be fragrant and aromatic.

Step 3: Season the Lamb

• Place the leg of lamb in a roasting pan. Choose a roasting pan that is large enough to comfortably hold the lamb without overcrowding. A roasting pan with a rack is ideal, as it elevates the lamb and allows for better air circulation and even cooking. If you don’t have a rack, you can use chopped vegetables like onions, carrots, and celery to create a makeshift rack.
• Using your hands, generously rub the herb and garlic mixture all over the leg of lamb. Ensure you coat every surface of the lamb, including the top, bottom, and sides. Massage the rub into the meat to help it penetrate and infuse the lamb with flavor. Pay special attention to getting the rub into any crevices or scored areas.
• If using, pour dry white wine or chicken broth into the bottom of the roasting pan. Pour the liquid around the lamb, not directly over it. The liquid will create steam during roasting, which helps to keep the lamb moist and prevents it from drying out. It will also create flavorful pan drippings that can be used to make a delicious gravy or sauce.

Step 4: Roast the Lamb

• Roast in the preheated oven for approximately 20-25 minutes per pound for medium-rare, or 25-30 minutes per pound for medium. These are general guidelines, and the exact cooking time will depend on the size and thickness of your leg of lamb, as well as your oven’s accuracy. It’s crucial to use a meat thermometer to ensure the lamb is cooked to your desired doneness.
• For medium-rare, aim for an internal temperature of 130-135°F (54-57°C). For medium, aim for 135-140°F (57-60°C). For medium-well, aim for 140-145°F (60-63°C). For well-done, aim for 145-150°F (63-66°C). Insert a meat thermometer into the thickest part of the lamb, avoiding the bone. Take the temperature reading a few times during the last hour of cooking to monitor progress. Remember that the internal temperature will continue to rise slightly during resting.
• Baste the lamb with pan juices every 30-45 minutes during roasting. Basting helps to keep the lamb moist and adds flavor. Use a bulb baster or spoon to drizzle the pan juices over the lamb. If the pan juices are starting to evaporate too quickly, you can add a little more wine or broth to the pan.
• If the lamb is browning too quickly, tent it loosely with foil. If the top of the lamb is becoming too dark before the internal temperature is reached, loosely cover it with a piece of aluminum foil. This will prevent further browning while allowing the inside to continue cooking.

Step 5: Rest and Serve

• Once the lamb reaches your desired internal temperature, remove it from the oven and tent loosely with foil. Resting is a crucial step that allows the juices to redistribute throughout the meat, resulting in a more tender and flavorful roast. Tent the lamb loosely with foil to keep it warm while it rests.
• Let the lamb rest for at least 15-20 minutes before carving. During resting, the internal temperature will continue to rise slightly (carry-over cooking). Do not skip this step, as it significantly improves the texture and juiciness of the lamb.
• Carve the leg of lamb against the grain. To carve, locate the grain of the meat (the direction of the muscle fibers) and slice perpendicular to it. This will result in more tender slices. Start by slicing around the bone to remove the meat, then slice the meat into even portions.
• Serve immediately and enjoy! Serve your beautifully roasted leg of lamb while it’s still warm and juicy. Pair it with your favorite side dishes and enjoy the delicious flavors.