Here's another one from allrecipes. It's probably against some cosmic law to make gyros with chicken, but when it's all you got, it's all you got! These were so good, though!
3 skinless, boneless chicken breast halves - cut into 1/2 inch strips
2 tablespoons ketchup
2 tablespoons olive oil
1 1/2 teaspoons white wine vinegar
1 teaspoon dried oregano
1 teaspoon mustard powder
1 1/2 teaspoons curry powder, or to taste
4 pita breads, cut in half
2 cups mixed salad greens
1 cup plain yogurt
Place the chicken strips side by side in a broiling pan. In a cup or small bowl, stir together the ketchup, olive oil, white wine vinegar, oregano, mustard powder and curry powder. Pour over the chicken. Allow the chicken to marinate while you preheat the oven's broiler.
Broil uncovered for 15 minutes with the meat about 6 inches from the heat. Just until the chicken is cooked through, but not browned. If left too long, it will turn stringy and dry.
Place hot chicken into pita pockets and spoon some of the juices from the pan over it. Top with salad greens and plain yogurt.