Chicken Souvlaki Salad

Name: Chicken Souvlaki Salad
Ingredients: 1 1/2 pounds skinless, boneless chicken breasts, cut into 1-inch cubes; Grated zest of 1 lemon, plus 2 tablespoons lemon juice; 3 tablespoons extra-virgin olive oil; 2 teaspoons dried oregano; Kosher salt and freshly ground pepper; 2 whole-wheat pitas, cut into 1-inch pieces; 1/2 cup nonfat plain Greek yogurt; 2 hearts romaine lettuce, chopped; 1 cup halved cherry tomatoes; 1/2 English cucumber, thinly sliced; 1/2 cup crumbled feta cheese