Wash the tomatoes, cucumber, onion and garlic and peel them. Cut the cucumber into slices, and the onion and tomatoes into semicircular slices. Wash the lettuce, cilantro and parsley and dry with paper towels. Finely chop the parsley. Wash the chicken fillet.
Prepare the marinade for the meat. Cut the chicken into small pieces, place in a bowl and add thyme, cumin, oregano, salt, pepper and 2 tbsp. l. olive oil. Mix thoroughly, cover with foil or cling film and refrigerate for 15 minutes.
Make the sauce. Place garlic, cucumber slices, cilantro into a blender and chop everything together. Add yogurt, olive oil and mix the sauce.
Fry the chicken fillet. Heat a little olive oil in a frying pan over medium heat, add the chicken and fry for no more than 10 minutes so that the meat does not become dry, stirring occasionally.
Assemble the gyros. Fry the pitas in a dry frying pan over moderate heat for 1 minute on each side. Place meat, lettuce, onion and tomatoes on one half of the pita. Pour the sauce on top and fold the pita in half.
Before serving, you can place a small pile of parsley on a plate with gyros and place a small gravy boat with tzatziki next to it. If you don’t have a gravy boat, you can spoon out the tzatziki in a small mound, just like parsley.