Heat the olive oil in a large pot over medium heat.
Add the onion and garlic and cook until the onion is translucent, about 5 minutes.
Add the carrots, potatoes, vegetable broth, thyme, bay leaf, salt, and pepper. Bring to a boil, then reduce the heat and simmer for 20 minutes, or until the vegetables are tender.
Remove the bay leaf from the pot.
Using an immersion blender, blend the soup until smooth. Alternatively, transfer the soup to a blender and blend in batches until smooth.
Return the soup to the pot and heat over low heat until warmed through.