01 - Melt butter in a large pot over medium heat. Add onions, celery, and garlic. Sauté for 4-5 minutes until softened but not browned, stirring occasionally to prevent sticking.
02 - Add diced potatoes and bay leaf to the pot. Stir thoroughly to coat vegetables in butter, allowing flavors to begin melding.
03 - Pour in vegetable broth. Bring mixture to a boil, then reduce heat to low. Simmer covered for 20 minutes until potatoes are very tender and easily pierced with a fork.
04 - Remove and discard bay leaf. Using an immersion blender, purée soup until completely smooth and velvety. Alternatively, blend in batches using a countertop blender, then return to pot.
05 - Stir heavy cream into puréed soup. Heat gently over low heat until warmed through—avoid boiling to prevent cream separation. Season with salt and pepper to taste, adjusting as needed.
06 - Ladle hot soup into individual bowls. Generously sprinkle fresh chives over each serving and add a swirl of extra cream if desired. Serve immediately.