- 1 well-trimmed 4-to 4 1/2-pound boneless leg of lamb with shank end removed
- 4 large garlic cloves; 3 chopped, 1 sliced
- 2 teaspoons finely grated lemon peel
- 20 fresh sage leaves (about), divided
- 4 ounces thinly sliced pancetta (Italian bacon)
- 3 tablespoons fresh lemon juice
- 3 tablespoons extra-virgin olive oil
- Caramelized Lemon Jus
- Open lamb, boned side up, like book. Trim most sinew and fat, being careful not to cut any holes in meat. Make one 3/4-to 1-inch-deep full-length cut in each thick portion of lamb (do not cut through to work surface). Cover lamb with sheet of plastic wrap. Using rolling pin, pound to even 1- to 1 1/2-inch thickness (lamb will be about 8×19 inches).
- Peel off plastic wrap. Sprinkle lamb evenly with salt and pepper, chopped garlic, and lemon peel. Top with 15 sage leaves, spaced evenly apart. Cover with pancetta. Starting at 1 long side, fold lamb in half. Tie lamb tightly at 2-inch intervals into long roll. Using small knife, make deep slits in lamb and insert slice of garlic and piece of sage leaf in each slit. Sprinkle lamb with salt and pepper. DO AHEAD: Can be made 1 day ahead. Cover and chill.
- Whisk lemon juice and oil in medium bowl; season with salt and pepper. Brush mixture all over lamb and let stand at room temperature 1 hour.
- Prepare barbecue (medium-high heat). Place lamb on grill and sear on all sides. Continue to grill until thermometer inserted into thickest part registers 130°F for rare, turning and brushing occasionally with lemon juice mixture, about 45 minutes. Transfer to cutting board. Let rest 10 minutes.
- Cut lamb into 1/2-inch-thick slices. Serve with Caramelized Lemon Jus.