1. On a clean work surface, place the chicken breasts on a large piece of plastic wrap, and fold the plastic wrap over to cover the chicken. Using a rolling pin or meat hammer, flatten the chicken until it is about 1/2 an inch thick. Season with salt and pepper.



2. On a grill or in a lightly oiled grill pan on the stove, cook each piece of chicken for about 5 minutes per side over medium heat. Set aside to cool, then cut each piece in half so you have four pieces of chicken.



3. To make each sandwich, spread 1 tablespoon of cilantro pesto on one slice of bread, then top with chicken, tomatoes, and a slice of cheese. Place second slice of bread atop cheese.



4. In a panini press on medium heat or in a skillet on the stove, cook panini until bread is lightly browned and cheese is melted — about 5 minutes in the panini press or 3 minutes per side in a skillet.

Makes 4 panini.