Prepare your smoker or pellet grill at 250 degrees using post oak, hickory, or pecan wood.
Remove any hard fat from the lamb and apply a light coat of olive oil as a binder.
Season the lamb with minced rosemary, Holy Cow, and Garlic and Herb. Allow to adhere for at least 15 minutes.
Place the lamb in the smoker, larger end towards the fire, and smoke until it reaches 165 internal temperature (about 4 hours for a 4.75lb leg of lamb).
While the lamb is smoking, mix all tzatziki sauce ingredients in a small bowl and refrigerate.
Remove the lamb from the smoker and place it in a ½ pan with garlic cloves. Cover with foil and return to the smoker until tender (around 203 internal temperature).
Remove the pan from the smoker, pull the lamb using two forks, and incorporate all the roasted garlic and jus from the cook. Discard the bone.
Lay down fresh pita bread and top with pulled lamb, homemade tzatziki sauce, diced cucumber, tomato, red onion, and feta cheese.
