1. Heat a grill pan over medium-high heat. Coat pan with cooking spray. Sprinkle 1/2 teaspoon salt and 1/4 teaspoon chipotle chile powder evenly over chicken; add chicken to pan. Cook for 6 minutes on each side or until done, and remove from heat.
2. Combine remaining 1/4 teaspoon salt, cucumber, tomatoes, onion, and remaining ingredients in a medium bowl, tossing well. Serve with chicken.