Line the baking sheet for easy cleanup!
If you want to avoid the possibility of some cheese running into the green beans, you can make an aluminum foil dam to split the baking sheet in half.
Don’t skip patting the chicken dry, or the cheese may slide off.
I recommend using a thicker pasty rather than oily pesto to help the cheese stick.
For extra browning, broil the chicken for the last 3-5 minutes.