In a large container with lid, make the spiced marinade by stirring the extra virgin olive oil, finely diced garlic cloves, spices, salt, and pepper to incorporate well, then add the yoghurt and combine well.
Add the chicken cubes to the spiced yoghurt marinade and use clean hands to rub it into the chicken, ensuring the pieces are completely coated with the marinade.
Pierce 4 chicken pieces onto each skewer, lay them down in the same container, ensuring they’re completely covered, put the lid on and marinate in the fridge from 1-hour minimum, ideally 4-6 hours.
In a small container with lid, vigorously stir the crushed garlic cloves, cup of natural yogurt and lemon juice to combine well, pop the lid on, and refrigerate.
Grease and heat a griddle pan or barbecue, then over medium-high grill the chicken skewers in batches for 4-5 minutes on one side, turn the skewers, then grill for another 4-5 minutes on the other side. Take care not to overcook the chicken; at this size they should take no more than 10 minutes to cook.
Transfer the chicken skewers one by one in the order you laid them down to an oven tray, cover securely with aluminium foil to keep them warm and let the skewers rest for 5 minutes.
While the chicken is resting, warm some pita bread on the griddle or grill and serve the skewers with the garlicky lemon yoghurt sauce, pickles, mezze such as hummus and baba ganoush, salads such as tabbouli or grilled vegetables.