Spicy Chicken Shawarma

Name: Spicy Chicken Shawarma
Ingredients: 1 teaspoon salt; 1 teaspoon crushed red pepper; 1/2 teaspoon ground ginger; 1/2 teaspoon ground cumin; 1/4 teaspoon ground coriander; 2 tablespoons plain low-fat Greek-style yogurt; 2 tablespoons fresh lemon juice; 2 garlic cloves, minced; 1 pound skinless, boneless chicken breast halves, thinly sliced; 2 tablespoons extra-virgin olive oil; 4 naan or whole wheat pita; 1/2 cup chopped cucumber; 1/2 cup chopped plum tomato; 1/4 cup chopped red onion; Prepared tzatziki sauce (to taste)