Melt the unsalted butter in a large pot over medium heat. Add the chopped onion and sauté for about 5 minutes until translucent. Then, add the minced garlic and cook for an additional minute.

Add the diced potatoes and pour in the vegetable broth, ensuring the potatoes are fully submerged. Bring to a boil, then reduce to a simmer and cook for 15-20 minutes until the potatoes are tender.

Blend the soup using an immersion blender until smooth. If you prefer a chunkier texture, blend only half of the soup.

Stir in the heavy cream, dried thyme, salt, and pepper. Heat over low until warmed through, being careful not to boil.

Serve the soup in bowls, garnished with shredded cheddar cheese and chopped green onions or chives. Pair with crusty bread or a fresh salad.