Veggie Pita Pockets

3 large tomatoes, sliced 1/4 (one-quarter) inch thick
1 medium cucumber, peeled and thinly sliced
1/4 (one-quarter) pound Feta cheese, crumbled
20 Greek-style black olives, pitted and cut in half
1 tablespoon fresh oregano
2 tablespoons olive oil
1 tablespoon balsamic vinegar
4 whole wheat pita breads, halved and opened into pockets

Layer the tomatoes and cucumbers in a small bowl. Add Feta cheese, olives, oregano, salt and pepper. Drizzle with oil and vinegar. Let stand 30 minutes. Cut each pita in halve and open envelope style. Divide tomato mixture into pita pockets. Wrap tightly in foil and chill. Yields four servings of two pita halves each.