To keep this soup allergy friendly, use coconut milk or other non-dairy milk in place of the cashew cream.
To make this in the Instant Pot, simply saute your onion, celery and carrot first on the saute setting. Add broth and chopped potatoes, secure lid and cook for 8 minutes on high pressure. Puree your cashews while it cooks. Allow pressure to release naturally for 10 minutes, release remaining pressure and puree soup with cashew mixture as desired. Cook time may vary slightly depending on the size of your potatoes.