In a medium bowl, combine minced garlic, dried oregano, paprika, cumin, lemon juice, olive oil, salt, and pepper to create a marinade.
Cut the chicken breasts into strips and add them to the marinade. Mix well and let marinate in the refrigerator for at least 30 minutes, ideally 2 hours for more flavor.
Preheat a grill or a grill pan over medium-high heat. Once hot, add the marinated chicken and grill for 6-8 minutes on each side until fully cooked and golden brown.
While the chicken is grilling, prepare the tzatziki sauce by combining Greek yogurt, diced cucumber, minced garlic (if desired), dill, and a pinch of salt in a bowl. Mix well and refrigerate until ready to use.
Once the chicken is cooked, remove it from the grill and let it rest for a few minutes before slicing it into smaller pieces.
Warm the whole wheat pitas on the grill for about 1 minute on each side.
To assemble the gyros, take a pita and add a generous amount of chicken strips, followed by diced cucumber, halved cherry tomatoes, and sliced red onion.
Drizzle the tzatziki sauce over the top and garnish with fresh parsley.
Fold the pita in half and enjoy your homemade Mediterranean Chicken Gyros!
Notes
For best flavor, marinate the chicken for at least 2 hours.