Pour the olive oil into a large pan and place it over medium high heat. Add the onions and peppers and season with salt and pepper to taste. Cook for 3-5 minutes or until vegetables have started to soften
Add the chicken to the pan and cook for 10 minutes, stirring frequently, until chicken is browned and cooked through. Stir in the lime juice.
Preheat the broiler. Divide the chicken and pepper mixture evenly over the rolls and top each sandwich with ¼ cup cheese. Place on a baking sheet and broil for 3-5 minutes or until cheese is melted. Top with chopped cilantro if desired and serve immediately with lime wedges on the side if using.