Greek Tzatziki Tuna Pitas

Name: Greek Tzatziki Tuna Pitas
Prep time: 20 min
Total time: 20 min
Cuisine: European, Mediterranean, Greek
Ingredients: 4 (5-oz) cans wild-caught tuna, drained and flaked; 1 (8-oz) pkg diced red onion; 1 (8-oz) container refrigerated tzatziki sauce; 1 English cucumber, coarsely chopped; 1 cup grape tomatoes, quartered; 1/2 cup crumbled feta cheese; 1/4 cup pitted kalamata olives, halved; 6 (6-inch) pita bread rounds