When sautéing your veggies and creating the roux at the beginning, allow the flour mixture to cook long enough to turn slightly browned. The browning of the flour ensures that it's been cooked for safety purposes, but also ensures that there's no raw flour taste in your final dish.
After you've got your flour mixture cooked, be sure to add the chicken stock one cup of the broth at a time. You took the extra step to make your own cheese sauce, allow it to properly thicken so you can enjoy all of that cheesy flavor!
Honestly you can serve it in a regular bowl, but nothing beats a Panera soup served out of a bread bowl. Splurge for a bread bowl!
If you don't have an Instant Pot, you can definitely make this copycat Panera Broccoli Cheese Soup on the stove top. Follow all the same directions, however you'll need to cook the broccoli in the hot soup for 8-10 minutes until it's tender before adding the whole milk and cheese.