Chicken Gyro Salad with Creamy Tzatziki Sauce

For the Tzatziki Sauce:

• 1 cup plain greek yogurt
• 1 hothouse cucumber
• 1 lemon, zested + 1 tablespoon juice
• 1 tablespoon olive oil
• 1 clove garlic, minced
• 1 tablespoon fresh chopped dill
• 1/2 teaspoon salt
• 1/4 teaspoon pepper

For the Chicken:

• 1 pound boneless skinless chicken breast
• 1 tablespoon red wine vinegar
• 2 tablespoons olive oil
• 1 clove garlic, minced (large)
• 1 teaspoon dried oregano
• 1/2 teaspoon crushed dried rosemary
• salt and pepper

For the Salad:

• 2 pieces flatbread
• 1 cup fresh mint leaves
• 1 small red onion, sliced thin
• 1 cup sliced cucumber
• 1 cup sliced tomato wedges
• 6 cups chopped romaine lettuce (2 cups for classic gyros)