Peel and dice the potatoes. To prepare the leeks, remove the dark leaves from the top. Trim the root and wash between the layers. Chop into a small dice. Mince the garlic and set aside. Tie the fresh thyme and bay leaves together with twine to make a bouquet garni.
In a large, heavy bottomed pot, heat the olive oil over medium heat. Add the leeks and sprinkle with a little kosher salt. Sauté for 4 to 5 minutes until the leeks have softened. Add the minced garlic and sauté for another minute until fragrant.
Add the vegetable broth, kosher salt, pepper, and bouquet garni along with the diced potatoes. Bring to a simmer and then reduce the heat to medium low. Simmer for about 10 minutes until the potatoes are about halfway cooked. Add the white beans and bring to a simmer. Cook for another 10 minutes or until the potatoes are tender.
When the potatoes are tender, the soup is done. If desired, you can thicken the soup slightly by crushing a few spoonfuls of the potatoes into the broth. Taste and adjust the seasoning if needed. Serve the soup topped with a dollop of sour cream and chopped fresh chives. Enjoy!