Add your potatoes, garlic & onion to the Instant Pot on sauté mode and stir in your spices. Let cook till onions are translucent, about 5 minutes. Alternatively, you could use a regular pot on the stovetop for this recipe.
Add your veggie broth and let simmer for 10 minutes, till potatoes are fork tender.
Add your cucumbers and oat milk, simmer another 15 minutes.
Using an immersion blender, blend until smooth and creamy. Or blend in small batches in a regular blender, taking care as this soup is very hot. If using a Vitamix, take the center plug out of the lid and cover with a towel so it doesn't explode.
Let cool 10-20 minutes before serving. Top with fresh dill and cracked black pepper. Enjoy!