COOK IT.
Heat the FORCE Grill to medium-high. Wrap garlic head in foil and place into the closed Grill to start cooking while the Grill preheats. Cook garlic for 15-20 minutes until soft when squished with some tongs. Allow to sit aside until cool enough to handle.
In a small bowl, mix together the oregano leaves, garlic powder, lemon juice, olive oil, salt and pepper. Place lamb in a large dish and coat in the marinade, massaging into the meat. Allow to marinate for 1 hour at room temperature if you have the time.
Place the marinated lamb straight onto the grill. Cook for 10 minutes on each side, remove and allow to rest for 10 minutes.
While the meat is resting, remove the skins from the garlic flesh and mash with a fork until pureed. Add to a bowl with the remaining ingredients for the Grilled Garlic Tzatziki. Mix well to combine.
With the FORCE Grill still on, place pitta onto the grill for 1-2 minutes on each side until warm and slightly charred but not crispy. Remove and brush with the melted butter.
To serve, slice the lamb into thin 0.5cm (0.2 in) slices. Assemble your gyros with a generous spoon of the Grilled Garlic Tzatziki, the lettuce, tomato, cucumber and onion. Top with some juicy pieces of lamb.