Press SAUTE on Instant Pot. Heat butter, add minced garlic, and saute for 30 seconds.
Add onion and saute till they are soft and translucent.
Next, add broccoli, and vegetable broth (or water). Give a quick stir.
Close the lid securely, and turn the vent to "SEALING". Select the PRESSURE COOK/MANUAL (High Pressure) setting and set the cooking time to 3 minutes.
When the instant pot beeps, do a Quick Pressure Release.
Then add the spinach, milk, cheese, salt, and freshly ground pepper. Stir well.
Turn on the Saute and simmer for 1-2 minutes until the spinach is wilted. At this stage, press Cancel.
Use an immersion blender to puree the soup until smooth. ( Or transfer the mixture to a traditional blender or Vitamix in batches and puree until smooth).
If you think the soup is too thin, you can add cornflour slurry into the soup and boil for 2 minutes, this gives thick consistency. I like soup thin, so I did not add it.
The healthy Instant pot Broccoli Cheese Soup recipe is ready to serve.