Make the tzatziki sauce by grating the cucumber and squeezing out all moisture. In a bowl, mix the dried cucumber with Greek yogurt, minced garlic, lemon juice, fresh dill, salt, and pepper. Set aside.

Preheat your oven to 400°F (200°C) and place flatbreads on a baking sheet. Brush each flatbread lightly with about 1 tablespoon of olive oil.

In a medium bowl, combine the cooked chicken with 2 tablespoons olive oil, oregano, garlic powder, and lemon zest. Mix thoroughly.

Spread the seasoned chicken mixture evenly over both flatbreads, leaving about a half-inch border around the edges.

Bake for 8-10 minutes until the flatbreads turn golden at the edges and the chicken is heated through.

Remove the flatbreads from the oven and immediately top with diced cucumber, red onion slices, cherry tomatoes, Kalamata olives, and crumbled feta cheese.

Drizzle generously with tzatziki sauce, sprinkle with fresh dill, cut into wedges, and serve immediately.