Chop the onion into small pieces and mince the garlic. Heat a large heavy-bottomed pot over medium heat, then add the olive oil. Once shimmering, sauté the onion and garlic until fragrant and translucent, about 5 minutes, filling the kitchen with a sweet aroma.
Add the peeled and diced potatoes to the pot. Stir them around with the sautéed onion and garlic, allowing the potatoes to absorb the flavors for a minute or two.
Pour in the vegetable broth, making sure it covers the potatoes. Increase the heat to bring the mixture to a gentle boil. Once bubbling, reduce the heat to low and let it simmer for about 15-20 minutes, or until the potatoes are tender and easily pierced with a fork, filling the air with the comforting scent of cooked potatoes.
Use an immersion blender directly in the pot to blend the soup until completely smooth and velvety. Alternatively, transfer the hot mixture carefully in batches to a blender, blending until silky and smooth, then returning it to the pot.
Stir in salt and pepper to taste, adjusting the seasoning to your preference. If the soup is too thick, add a splash more broth and stir to loosen it. Let it simmer for another 5 minutes to meld the flavors.
Turn off the heat and let the soup rest for a few minutes. Serve hot, garnished with fresh herbs if desired, and enjoy the creamy, comforting bowl that’s perfect for chilly nights.