Wash and peel the potatoes. Cube them into 1-inch chunks, then add them to a large stockpot with the chopped onions, celery, and water.
Bring the water to a boil, then reduce the heat to simmer for 25-30 minutes (10 minutes in an Instant Pot), or until the potatoes are fork-tender.
In the meantime, make your own cashew cream by blending 1 cup of soaked raw cashews with ¾ cup of water. Set aside for later.
Partially or fully blend the soup with an immersion blender. Or, mix the water and vegetables in a blender, then transfer back to the pot.
Stir in ¾ cup of cashew cream. Taste and season with salt and pepper to your liking, and add more water or cashew cream until it reaches your preferred consistency.
Serve with garnishes like chopped green onions, chives, shredded vegan cheese, tempeh bacon, etc. Happy eating!
Notes
Don't drain the water: Use the boiling water as the broth so you don't lose any flavor. Plus, the excess starch will help thicken the soup.
Cook long enough: To ensure a smooth and creamy soup consistency, cook the potatoes until they are very tender.
Chop the potatoes evenly: To make sure everything is cooked the same, cut the potatoes roughly the same size.
Soak the nuts: Soak the cashews in room temperature water overnight or in boiling water for 1 hour.
Quality ingredients: Choose high-quality, fresh ingredients for the best flavor in this 4-ingredient potato soup.
Consistency: Adjust the amount of water or cashew cream to achieve your desired soup consistency.
Adjust accordingly: Taste the soup as you go and adjust seasonings to suit your preference.
Cool before blending: Allow the soup to cool slightly before blending to avoid splatters and burns.
Big batch: Double the recipe for meal prep or for a big crowd.
Nutritional information is a rough estimate and should not be taken as health advice.