- Add all ingredients (except lemon juice, spinach and Parmesan cheese) to pressure cooker. 
- Set to High Pressure. Cook for 15 minutes. Quick release. 
- Shred chicken & add back to the soup. Add lemon juice and spinach. 
- Top with Parmesan cheese before eating. 
- Note: if you don't have a pressure cooker, you can use a slow cooker instead. Cook for 3 - 4 hours on high or until chicken is at least 165 degrees.