1. Cut the mozzarella into 2 long strips. Place each chicken breast on a sheet of microwave-safe plastic wrap. With a sharp knife, slice each breast horizontally until cut almost in half. Season the inside with salt and pepper. Spread pesto inside and insert a strip of cheese in each breast. Roll up tightly in plastic wrap.
2. Pour 3 cups of water into the bowl. Place the rolls in the steam basket and place the basket in the Prep&Cook bowl. Launch the P1 steam program for 15 minutes. Turn rolls over. Launch steam program for another 10 minutes.
3. At the end of cooking, remove the plastic wrap. Slice and serve.