In a gallon zippered bag, add chicken and oil. Combine seasonings for chicken and then add to bag. Zip up bag and smoosh around chicken until all evenly coated with seasoning.
If making tzatziki fresh from recipe below, put that together and then place in refrigerator until ready to build.
Preheat oven to 400degF.
In large saute pan over medium high heat, add seasoned chicken. Saute and flip for around 20 minutes, to ensure all pieces are cooked through.
Line pitas out on a baking sheet and place in oven for 5-7 minutes, until warmed
To build a pita, start with warmed pita and layer on lettuce, tomato, onion and cucumber. Add on 4-5 strips of chicken then top with tzatziki and sprinkle with feta cheese.