Heat a grill pan over medium-high heat. Coat pan with cooking spray. Sprinkle steak evenly with salt and pepper. Add steak to pan; cook 6 minutes on each side or until desired degree of doneness.

Remove steak from pan; let stand 10 minutes.

Add onion to pan; cook 3 minutes on each side or until lightly browned. Remove from pan; cool.

Combine ketchup and next 4 ingredients (through chipotle chile powder) in a large microwave-safe bowl, stirring well. Microwave at HIGH 1 minute or until thoroughly heated.

Cut steak diagonally across grain into thin slices. Add steaks to ketchup mixture; toss to coat.

Divide steak mixture evenly among bottom halves of rolls; top each serving with one onion slice. Place top half of roll on each sandwich.

Yield: 4 sandwiches