Set the Instant Pot to "Sauté" mode. Add oil to the inner pot. Once hot, add onion and garlic. Saute for a couple of minutes.
Add cubed zucchini, peeled and cubed potato, salt and vegetable broth.
Close the lid, and pressure cook for 10 minutes.
Once the cooking cycle is complete, allow the Instant Pot to naturally release pressure for 7 minutes.
After 7 minutes, release the pressure manually. Carefully open the Instant Pot lid and use an immersion blender to blend the soup until smooth. Alternatively, transfer the soup to a blender in batches, blend, and return to the pot.
Add coconut milk and simmer for 2 minutes.
Taste the delicious soup and adjust the seasoning if necessary. Add more salt and black pepper to suit your preferences.
Ladle the soup into bowls. Garnish with fresh parsley, grated Parmesan cheese, or a dollop of sour cream, if desired.
Serve the Vegan Instant Pot Zucchini and Potato Soup hot with your favourite bread on the side.