Chicken Marinade:

• 2 pounds boneless skinless chicken breasts
• 2 Tablespoons olive oil
• 2 Tablespoons lemon juice
• 2 teaspoons smoked paprika (or regular paprika)
• 2 teaspoons ground cumin
• 2 cloves garlic, minced
• 1 teaspoon ground turmeric
• 1 teaspoon ground coriander
• 1 teaspoon kosher salt
• 1/4 teaspoon freshly ground black pepper
• 1/4 teaspoon onion powder
• 1/4 teaspoon ground cinnamon
• 1/8 teaspoon crushed red pepper flakes (or more to taste)

Tzatziki Sauce:

• 1 cup plain Greek yogurt
• 2 cloves garlic, minced
• 1/2 teaspoon dried dill weed
• 2 teaspoons lemon juice
• Salt and freshly ground black pepper, to taste
• 1 inch piece of English cucumber, peeled and finely diced

For Serving:

• 6 pitas or flatbreads
• 1 small romaine heart, chopped
• 1 cup cherry tomatoes, halved
• 1/2 of a red onion, thinly sliced
• 1/2 of an English cucumber, thinly sliced
• Crumbled feta cheese (optional)