In a large pot over medium heat, sauté the garlic and onions for 3-4 minutes. I like to use splashes of water to keep them from sticking. You can also use a tbsp of oil if you prefer. Then add the potatoes, celery, carrots, rosemary, thyme and vegetable broth and bring to a boil. Once it's boiling, lower the heat and allow it to simmer for about 15-20 minutes. The potatoes should be fork tender.
Add in the cashew sour cream and use an immersion blender or regular blender to blend up about half the soup. If you dont have either you can use a potato masher and mix it all together. Taste the soup and add salt and pepper. Then top with things live chives, green onions, vegan cheese or any other toppings you like on a baked potato because they go great in this soup!