Mediterranean Tuna Pita

12 ounces canned flaked tuna, drained (2 cans) 1/4 cup plain yogurt 1/4 cup mayonnaise 2 tablespoons finely chopped onion 1 teaspoon dry basil 1/2 teaspoon garlic powder 1/4 teaspoon black pepper 1 tomato, sliced 1/2 cup cucumber slices 1/4 cup olives, chopped (black or green) 2 pita bread rounds 1. Combine tuna, yogurt, mayonnaise and seasonings; mix well. 2. Cut pita bread in half; split to form pockets. 3. Fill pockets with tomato, cucumber, tuna mixture and olives.