In a large pot, heat the olive oil over medium heat. Add the chopped onion and sauté for about 5 minutes until it becomes translucent. Add the minced garlic and cook for another minute until fragrant.

Add the diced potatoes to the pot along with the vegetable broth, thyme, salt, and black pepper. Bring the mixture to a boil, then reduce the heat and let it simmer for about 20 minutes, or until the potatoes are tender.

Once the potatoes are cooked, use an immersion blender to puree the soup until smooth. If you don’t have an immersion blender, carefully transfer the soup in batches to a regular blender and blend until smooth.

Return the blended soup to the pot and stir in the heavy cream. Heat the soup over low heat for an additional 5 minutes, stirring occasionally. Adjust seasoning if necessary.

Serve the soup hot, garnished with chopped chives and shredded cheddar cheese if desired.