In a mixing bowl, whisk together olive oil, lemon juice, minced garlic, oregano, paprika, and a pinch of salt and pepper until blended.

Cut chicken breast into bite-sized chunks and coat thoroughly with marinade. Cover and marinate in the fridge for at least 15 minutes.

Prepare the salsa by dicing cucumber, tomatoes, bell pepper, and red onion. Combine with parsley, feta, lemon juice, salt, and pepper. Let sit.

Heat a skillet over medium-high heat, cook marinated chicken for 3-5 minutes per side until golden brown and cooked through.

Warm pitas either over a gas flame or in a skillet until pliable.

Assemble tacos by placing chicken in pitas, topping with salsa and tzatziki. Serve immediately.