In a mixing bowl, combine the salt, black pepper, lemon juice, nutmeg (if using), and olive oil. Whisk together until well blended. Add the mixed herbs, feta cheese, chopped figs, and pistachios to the bowl, and stir gently to combine.
Place the boneless leg of lamb in a large roasting pan. Pour the herb and feta marinade over the meat, ensuring it is fully coated. Cover the pan with plastic wrap or foil and refrigerate for at least 4 hours, or overnight for the best flavor.
When you’re ready to cook, preheat your oven to 375°F (190°C).
Remove the lamb from the refrigerator and let it sit at room temperature for about 30 minutes. Place the roasting pan in the preheated oven and roast the lamb for approximately 1 ½ to 2 hours, or until the internal temperature reaches 135°F (57°C) for medium-rare.
Once the lamb is done, remove it from the oven and cover it loosely with aluminum foil. Let it rest for at least 15 minutes before slicing.
