Start by cooking the potato, onion, and carrot (for the sauce) in a pot of boiling water until vegetables are tender.
In another pot, sauté the onion with the olive oil until translucent then add the minced garlic.
Add the broccoli florets and continue cooking for about 5 minutes.
Add the water and close the pot lid and cook for about 15 minutes on low.
Meanwhile, mix the sauce ingredients in a blender with the spices and reserved vegetable water.
Add the sauce and black pepper to the soup and simmer for a few minutes then add the plant milk and simmer until creamy.