Greek Turkey Meatball Gyro with Tzatziki

Name: Greek Turkey Meatball Gyro with Tzatziki
Ingredients: turkey meatball:; * 1 lb ground turkey; * 1/4 cup finely diced red onion; * 2 garlic clove, minced; * 1 teaspoon oregano; * 1 cup chopped fresh spinach; * salt and pepper to season; * 2 tablespoon olive oil; tzatziki sauce:; * 1/2 cup plain greek yogurt; * 1/4 cup grated cucumber; * 2 tablespoon lemon juice; * 1/2 teaspoon dry dill; * 1/2 teaspoon garlic powder; * salt to taste; * 1/2 cup thinly sliced red onion; * 1 cup diced tomato; * 1 cup diced cucumber; * 4 whole wheat flatbread