Preheat the oven to 200 C.
Chop the chicken into bite-sized pieces. Toss with salt, oil and all the spices listed above. Lay the pieces out on a large baking tray without overlaps.
If the pieces are too tightly packed on the tray, they will braise and not colour very well. Do this in two trays if necessary.
Roast in the oven for 30-35 mins or until nicely browned.
Meanwhile make the tzatziki: grate the cucumbers with their skins on. Take handfuls of the cucumber and squeeze out all the excess moisture out of them. We don’t want this. Alternatively, add the grated cucumber to a sieve and squeeze out excess moisture.
Mix together the cucumber, yogurt, garlic and salt in a bowl. Taste and adjust seasoning. Refrigerate until ready to serve.
To serve, spread a layer of tzatziki on your plate. Top with shredded lettuce. Add the chicken pieces on top. Spoon the remaining oils and chicken juices from the baking tray over the top. I like this dish best when the chicken is hot and the tzatziki is fridge-cold.
Serve as is or with flatbreads on the side.