Heat your oven to 180°C/Fan 160°C/Gas 4. Peel and grate the garlic, then put in a dish. Finely grate in the lemon zest. Add 1 tbsp oil and some salt and pepper, then whisk together. Add the chicken and turn to coat it in the oil.
Tip the chicken onto a baking tray and spread out in an even layer. Slide into the oven on the top shelf and roast for 25-30 mins till golden brown and cooked through.
Pop 2 tortilla wraps on a baking tray and slide into the oven on the middle shelf, below the chicken. Bake for 15 mins till golden brown and crisp. Set aside to cool.
While the chicken and tortillas cook, prepare the veg. Trim the lettuce and shred the leaves. Scoop them into a large bowl. Peel the cucumber, then halve and roughly chop it. Add to the lettuce.
Quarter the cherry tomatoes and add them to the bowl. Trim the roots off the spring onion and very finely shred it. Finely slice the mint leaves. Add them both to the bowl. Toss everything together.
Squeeze the juice from half the lemon into a small bowl. Add 1 tsp sumach, 1 tbsp olive oil and a pinch of salt and pepper. Whisk together with a fork. Taste and add more salt and pepper if you think it needs it. Add to the salad and toss to mix.
Break the tortillas into small pieces and add them to the salad bowl. The chicken should be ready by now, so tumble that into the bowl as well. Toss to mix, then divide between 2 warm bowls and serve straight away.