Given the task definition and input, reply with output. In this task, you have to identify the named entities (NER) which are the ingredients required given its directions. Named entities are the names of the items without their quantity.

Heat grill to medium heat., Mix 1/4 cup Lemony Spinach-Parmesan Pesto and cheese., Cut lengthwise slit in thickest side of each chicken breast, being careful to not cut through to opposite side., Stuff with cheese mixture., Close pockets; secure with wooden toothpicks., Spray chicken with cooking spray., Grill 5 min., on each side or until done (165F)., Serve topped with remaining pesto.
Mozzarella Cheese, chicken breasts