Spray Instant Pot™ insert with cooking spray. Mix broth, rice, salt and pepper in insert.
Stir in chicken and broccoli. Secure lid; set pressure valve to SEALING. Select MANUAL or PRESSURE COOK ; cook on high pressure 10 minutes. Select CANCEL. Set pressure valve to VENTING to quick-release pressure.
Stir in cheese. Broccoli will break down when stirring.