Bring a medium pot of salted water to the boil. Preheat BBQ grill or hot plate to medium-high (if using). Prepare ingredients. Pat lamb dry. Add to a medium bowl with all remaining za'atar rubbed lamb ingredients and toss to coat lamb well. Set aside to marinate.
Cook freekeh in pot of boiling water for 14-15 minutes, until tender with a slight bite. Drain well.
Whisk mustard, oil, vinegar and salt together in a large bowl. Peel carrots into ribbons and thinly slice cores; cut tomatoes in half; tear lettuce into bite-sized pieces. Place all in bowl with vinaigrette.
Heat a large, dry fry-pan on medium-high heat. Cook lamb for about 3 minutes each side for medium (depending on thickness), or until cooked to your liking. Alternatively, cook on BBQ. Set aside, covered, to rest for 2–3 minutes then slice thinly, reserving any resting juices.
While lamb is resting, combine harissa spice mix and hot water in a small bowl and let sit for 5 minutes. Add yoghurt and honey and mix until smooth. Chop mint leaves.
Add cooked and drained freekeh to bowl with salad ingredients. Add lamb and any resting juices (if desired) to salad, gently toss to combine and season.
TO SERVE spoon za'atar rubbed lamb with freekeh salad onto plates. Dollop over harissa yoghurt and garnish with mint and a lemon wedge for squeezing.