Step 1 Preheat oven to 160°C. Place cracked wheat into a large, heatproof bowl. Cover with boiling water. Set aside for 20 minutes, or until softened. Rinse under cold running water. Drain, pressing out water with a metal spoon.
Step 2 Meanwhile, place pita pockets onto a large baking tray. Bake for 8–10 minutes, turning once, or until golden and crisp. Remove, cool, then break pita pockets into bite-sized pieces.
Step 3 Sprinkle lamb evenly with sumac. Place a large chargrill pan over high heat and spray with oil. Grill lamb for 2–3 minutes each side, or until cooked to your liking. Remove, cover loosely with foil and set aside to rest for 2–3 minutes. Thinly slice.
Step 4 Place cracked wheat, tomatoes, cucumber, shallots, herbs, extra sumac and pita pocket pieces into a large bowl. Gently toss to combine. Serve topped with a quarter of the sliced lamb and a dollop of tzatziki.