Tip the chicken into a large bowl and add the marinade ingredients, along with 1 tsp salt and plenty of black pepper. Mix well, ensuring each thigh is well coated. Cover and chill for at least 3 hrs, or up to 48 hrs if you have time.
A few hours before you want to eat, make the pitta. In a bowl, mix the flour, yeast, sugar and 1/ 2 tsp salt with your fingertips. Add 150ml lukewarm water and 2 tsp olive oil, and combine to a dough. Tip onto a work surface and knead for 8-10 mins (or use a tabletop mixer for 5 mins). Clean, then lightly oil your bowl, return the dough and cover loosely with cling film. Leave to rise for 1 hr or until nearly doubled in size.
Divide the dough into four equal pieces. Roll out to circles, as thin as you can. Cover with sheets of oiled cling film and leave to rise for 15-20 mins.
To make the tzatziki, halve the cucumber lengthways and scoop out the seeds. Finely chop, then combine with the remaining ingredients, along with a pinch of salt. Chill until ready to serve.
Heat the grill to its highest setting. Line a roasting tin with foil and find 4 metal skewers long enough to sit across the top with a little space underneath. Remove the chicken from the fridge, take one thigh and thread it over 2 skewers, so it has a skewer through either side. Thread another piece of chicken on top, leaving a slight gap between each piece; you should fit 6 thighs on each pair of skewers. Position the skewers on top of the roasting tin and set aside while you finish the pittas.
Heat a large frying pan (or two if you have them) over a medium-high heat and brush the breads with oil. Gently lift one into the pan. It should sizzle, and bubbles should appear on the surface after 1-2 mins. When the underside is golden, flip it and cook for another 2-3 mins. Continue until all the breads are cooked, wrapping them in foil as you go. Keep the bread warm in the bottom of the oven while you cook the chicken. Alternatively, cook on the barbecue for 5-8 mins, turning occasionally.
Put the chicken under the hot grill and cook for 15-20 mins, brushing with oil and any juices from the bottom of the tin regularly, and turning halfway through cooking. Once cooked, remove from the oven and rest for 5 mins.
Cut through each pair of skewers to make four kebabs and serve in the warm bread, with lettuce, tomato, red onion, lemon wedges and tzatziki.
