Ingredients

• 1 shallot, chopped
• 2 garlic cloves, chopped
• 1/2 cup pine nuts
• 1/2 cup pitted Kalamata olives
• 1/4 cup drained oil-packed anchovies
• 1/4 cup finely grated lemon zest
• 1/4 cup mint leaves
• 1/4 cup parsley leaves
• 2 tablespoons thyme leaves
• 1/2 cup olive oil, plus more
• Kosher salt, freshly ground pepper
• 0 freshly ground pepper
• 1 3–4 pound piece butterflied boneless leg of lamb
• 2 cups soft sheep's-milk cheese or goat cheese
• 1 garlic clove, finely grated
• 2 teaspoons finely grated lemon zest
• 1/2 teaspoon thyme leaves
• 1/2 cup plus 1 tablespoon olive oil
• Kosher salt, freshly ground pepper
• 0 freshly ground pepper
• 1 bunch watercress, trimmed
• 1 tablespoon fresh lemon juice
• Flatbread (for serving)

Instructions

1. Preheat oven to 425°. Finely chop shallot, garlic, nuts, olives, anchovies, lemon zest, mint, parsley, and thyme in a food processor. With motor running, stream in 1/2 cup oil; process until blended. Season stuffing with salt and pepper.
2. Unfold lamb on a cutting board and season with salt and pepper. Spread stuffing over top; roll up lamb from left to right. Position seam side down and tie closed with kitchen twine at 1 1/2" intervals crosswise, then once lengthwise. Transfer to a wire rack set inside a rimmed baking sheet; drizzle with oil.
3. Roast until lamb is starting to brown, 30–40 minutes. Reduce temperature to 325° and continue to roast until a thermometer inserted into thickest part registers 125°, 35–45 minutes longer. Remove lamb from oven and tent with foil; let rest 15–20 minutes.
4. Do ahead: Lamb can be stuffed and tied 1 day ahead; cover and chill. Bring to room temperature before roasting.
5. Assembly: While lamb rests, process cheese, garlic, lemon zest, and thyme in food processor until light, fluffy, and smooth. With motor running, stream in 1/2 cup oil; process until blended. Season herbed cheese with salt and pepper. Dress watercress in a large bowl with lemon juice and remaining 1 tablespoon oil; season with salt and pepper. Slice lamb and serve with watercress, herbed cheese, and flatbread.
6. While lamb rests, process cheese, garlic, lemon zest, and thyme in food processor until light, fluffy, and smooth. With motor running, stream in 1/2 cup oil; process until blended. Season herbed cheese with salt and pepper.
7. Dress watercress in a large bowl with lemon juice and remaining 1 tablespoon oil; season with salt and pepper. Slice lamb and serve with watercress, herbed cheese, and flatbread.