Peel and dice the potatoes into roughly 2-cm cubes, keeping the pieces uniform for even cooking.
Heat the large pot over medium heat and add the olive oil, allowing it to warm until shimmering and fragrant.
Add the diced onion to the pot and sauté until translucent, about 5 minutes, until it begins to smell sweet and turns a soft, glassy appearance.
Stir in the minced garlic and cook for another minute until it releases a fragrant, nutty aroma.
Add the diced potatoes to the pot, stirring to coat them in the fragrant onion and garlic mixture.
Pour in the vegetable broth, ensuring the potatoes are submerged, then increase the heat to bring everything to a gentle boil.
Reduce the heat to low, cover the pot, and let the mixture simmer for about 20 minutes, or until the potatoes are tender when pierced with a fork.
Remove the lid and use an immersion blender to blend the soup directly in the pot until ultra-smooth and velvety, or carefully transfer to a blender in batches.
Stir in the plant-based milk or coconut cream for added richness, then season with salt and pepper to taste.
Allow the soup to simmer gently for another 2-3 minutes to meld the flavors, then taste and adjust seasoning as needed.
Serve the hot, creamy soup in bowls, garnished with fresh herbs if desired, and enjoy the cozy, comforting textures and aroma.