Combine the olive oil, lemon zest and juice, herbs, garlic powder, salt, and pepper in a large bowl. Add the lamb, cover in marinade and store in the refrigerator, covered, overnight or for up to 3 days.

Remove lamb from refrigerator and bring to room temperature. Prepare a charcoal grill until coals are hot coals or heat grates on gas grill and set temperature to 350 degrees. Grill on both sides until the internal temperature is 120 to 125 degrees for rare. This will take 40 minutes to 1 hour, depending on how hot the grill is. Baste lamb every 15 minutes. For added flavor make a herb basting brush. Tie herb together and table to a wooden stick or the end of a wooden spoon.

Remove the lamb to a cutting board, cover with aluminum foil, and allow to rest for 20 minutes. Slice and serve.

If you have a smoke box on your grill, I recommend adding a few sprigs of rosemary, thyme and tarragon to it for additional flavor.