Peel the potatoes and cut them into 2 cm cubes. Rinse them under cold water and set aside.
Heat the olive oil in a large pot over medium heat until it shimmers and starts to ripple, about 1 minute.
Add the diced onion to the pot and sauté until it becomes translucent and fragrant, about 5 minutes. Stir occasionally and listen for a gentle sizzling sound.
Stir in the minced garlic and cook for another minute until it releases a rich aroma, being careful not to burn it.
Add the cubed potatoes to the pot, stirring to coat them with the aromatic base. Pour in the vegetable broth, ensuring the potatoes are fully submerged.
Bring the mixture to a boil over high heat, then reduce the heat to low and cover the pot. Let it simmer gently for 15-20 minutes, or until the potatoes are fork-tender and soft.
Check the doneness by piercing a potato with a fork; it should slide in easily. Remove the pot from heat.
Use an immersion blender to carefully blend the soup directly in the pot until smooth and velvety. Alternatively, transfer it to a blender in batches, blending until creamy.
Return the blended soup to a gentle simmer. Stir in salt, freshly ground black pepper, and optional nutritional yeast or plant-based cream for added richness. Taste and adjust the seasoning as needed.
Let the soup sit off the heat for 5 minutes to allow flavors to meld. Serve hot, garnished with herbs or a drizzle of olive oil if desired.