1. Prepare the marinade. In the bowl of a small food processor, add garlic, oregano, paprika, salt, pepper, olive oil and lemon juice
2. Place chicken in a large bowl and Top with marinade. Toss to combine, making sure chicken is well-coated with marinade. cover tightly and refrigerate for 2 hours or overnight.
3. Prepare outdoor grill (or griddle). Brush grates with a little oil and heat over medium-high heat. t. Place chicken on the grill (or cook in batches on griddle) until well browned. Be sure to turn chicken evenly to cook on all sides, about 5 minutes total. (Adjust temperature of grill if necessary). While grilling, brush lightly with the marinade (then discard any left marinade).
4. Transfer chicken to a serving platter and let rest for 3 minutes. Meanwhile, briefly grill pitas and keep warm.
5. Assemble grilled chicken souvlaki pitas. First, spread Tzatziki sauce on pita, add chicken pieces then add veggies, feta  and olives.

Enjoy!