Marinate the sliced chicken with olive oil, lemon juice, garlic, oregano, salt, and pepper in a mixing bowl for at least 15 minutes.
Preheat the air fryer to 200°C (about 400°F).
Place the chicken in a single layer in the air fryer basket and cook for 8-12 minutes, flipping halfway through, until the internal temperature reaches 74°C (165°F).
Let the meat rest for a few minutes, then slice it against the grain.
Warm the pita bread and stuff with the sliced chicken, tzatziki sauce, and fresh toppings like onions, tomatoes, and lettuce.
Serve immediately and enjoy your delicious gyros!
Notes
Tip: To avoid soggy pita, keep the sauce portions light and assemble right before eating.