1Spray rack or broiler pan with cooking spray. Heat coals or gas grill to low to moderate heat or set oven control to broil. Place chilies on grill or rack in broiler pan. Grill 4 to 5 inches from heat about 4 minutes, turning several times, until skin is blistered and charred. Place chilies in paper bag. Close tightly; let stand 15 minutes.
2Mix tomato paste, water, vinegar, Worcestershire sauce, mustard and thyme; set aside. Remove chilies from bag. Peel off skin; discard. Keep chilies warm.
3Rub both sides of pork with Cajun seasoning blend. Place pork on grill or rack in broiler pan. Grill 4 to 5 inches from heat about 4 minutes or until seasoning browns; brush with tomato sauce. Grill 1 minute; turn. Grill 3 minutes longer; brush with sauce. Grill 1 to 2 minutes or until pork is slightly pink in center.
4Heat remaining tomato sauce to boiling. Serve over pork and chilies.