It is recommended to make this a few hours in advanced so that the ingredients can marry together.
In a piece of cheesecloth, a strainer, or a towel, gently squeeze out any excess moisture from cucumbers.
In a bowl, mix together strained cucumber with remaining ingredients. Cover with plastic wrap and store in the fridge until needed. This stores in the refrigerator for a few days.
To make the marinated chicken:
It is recommended to marinate the chicken at least 1 hour in advance, or up to 3 hours before cooking.
In a disposable zipper bag, or a medium size bowl, combine the diced chicken meat with the oil. Sprinkle the seasoning evenly across the meat. Mix until the seasoning and oil are evenly coated across the pieces of meat.
Allow the chicken to marinate under refrigeration for 1-3 hours.
After marination, the meat can be skewered for easy grilling, or it can be roasted in the oven on parchment paper in a preheated 375F oven, turning the chicken meat halfway through cooking for a total of 12-15 minutes or until the chicken reaches 165F internal temperature. If grilling, grill for several 2-3 minutes each side on a preheated grill. You will want nice grill marks and an internal temperature of 165F.
To serve, wrap pita bread in aluminum foil and warm in the oven. Top warm pita with cooked chicken, tzatziki sauce, tomatoes, red onion and crumbled feta.
