1In medium saucepan over medium heat, melt butter. Add onion and cook until soft, 3-5 minutes, stirring occasionally. Add remaining sauce ingredients, stir and cook for 5 minutes. Turn heat to low.
2Brush chicken with olive oil and season with salt and pepper. Grill over direct medium heat. Grill chicken 8-10 minutes or until no longer pink in the middle. Turning once.
Remove from grill and let rest for 5 minutes.
3Shred chicken or slice thinly and add to sauce, stir and heat through.
Grill rolls if desired, until lightly toasted, 30-60 seconds.