Meanwhile, position rack in upper third of oven and preheat broiler. Coat a broiler pan with cooking spray. Sprinkle chicken with garam masala and salt. Place the chicken on the prepared pan; broil until no longer pink in the center and an instant-read thermometer inserted into the thickest part registers 165 degrees F, 4 to 8 minutes per side. Transfer the chicken to a clean cutting board and let rest for 5 minutes, then slice.