For the spice rub:
1 tsp. of kosher salt (optional)
1 tsp. of paprika
1/2 tsp. of ground cumin
1/4 tsp. of freshly ground black pepper
1/4 tsp. of cayenne pepper
For the cucumber yogurt:
1 cup of plain low-fat yogurt
1/2 small cucumber, peeled, halved, seeded, and diced (about 4 oz.)
2 tsp. of fresh lemon juice
1/4 tsp. of garlic, minced
1/4 tsp. of salt (optional)
1/8 tsp. of freshly ground black pepper
4 4-oz. boneless, skinless chicken breasts
1 tbsp. of olive oil for brushing
4 whole-wheat pita breads, warmed
1 small bunch of watercress, washed and dried (discard any tough stems)
1. Light the grill. To make the spice rub: Combine the salt, paprika, cumin, black pepper, and cayenne pepper in small bowl. Set aside.
2. To make the cucumber yogurt: Combine the yogurt, cucumber, lemon juice, and garlic in a medium bowl and season with salt and pepper. Set aside.
3. Pat the chicken breasts on both sides with the spice rub. Brush the chicken and the grill lightly with olive oil and grill chicken over direct heat, with the grill covered and the vents open. When the chicken breasts are marked by the grill, flip them over and finish cooking the other side until done. The time will depend on the heat of the grill, approximately 10 to 12 minutes total.
4. Remove the chicken breasts from the grill and cut them into slices. To serve, fill the warm pitas with sliced chicken and watercress, and drizzle a little cucumber yogurt into the sandwiches.