In a bowl, combine 3 tablespoons of olive oil, the juice of 1 lemon, 3 minced garlic cloves, 2 teaspoons of dried oregano, 1 teaspoon of ground cumin, 1 teaspoon of paprika, and salt and pepper to taste.

Coat the boneless chicken thighs or breasts in this marinade, ensuring they are completely covered. Cover the bowl and refrigerate for at least 1 hour, or overnight for even more flavor.

Mix together 1 cup of plain Greek yogurt, the grated cucumber (squeezed to remove excess moisture), 2 minced garlic cloves, 1 tablespoon of olive oil, 1 tablespoon of chopped fresh dill, and the juice of 1/2 lemon.

Season with salt and pepper to taste and chill this mixture in the refrigerator for at least 30 minutes to allow the flavors to meld.

Heat a skillet or grill pan over medium-high heat.

Place the marinated chicken in the pan and cook for about 4–5 minutes per side, until fully cooked through and golden brown.

Let the chicken rest for about 5 minutes before slicing it into tender strips.

While the chicken cooks, warm each pita bread in a dry skillet for 30 seconds per side.

Keep the warmed pitas wrapped in a clean towel to maintain their warmth.

Spread a generous amount of tzatziki sauce over each warm pita.

Add strips of the grilled chicken, and then top with sliced red onion, halved cherry tomatoes, crumbled feta cheese, and fresh lettuce leaves.

You can fold the pitas over or serve them open-faced for a colorful presentation.