Yogurt-Marinated Chicken & Creamy Greek Sauce

Ingredients

• 1 large chicken breast (about 1/2 pound)
• 1/2 cup plain, whole milk yogurt
• 2 tablespoons olive oil
• 1 teaspoon dried oregano
• 1/2 teaspoon kosher salt
• freshly ground black pepper, to taste
• 4 tablespoons mayonnaise (regular or light)
• 1 tablespoons milk
• 1 tablespoon cider vinegar
• 3/4 teaspoon sugar
• 1/8 garlic powder
• squeeze of lemon juice
• kosher salt and freshly ground black pepper
• 2 tablespoons olive oil
• 2 large garlic cloves, peeled and smashed
• 1/2 teaspoon dried oregano
• 1 tomato, diced
• 1/2 cucumber, diced
• pita bread, for serving