Start with the olive oil and Avalon butter in a soup pot over medium low heat and add the diced celery root/celeriac, celery, carrot, onion and garlic.
Cook the vegetables on medium low heat for 5 – 10 minutes, but do not brown.
Next add the diced/cubed potato and cauliflower and cook over medium heat for another 5 minutes.
Add the chicken stock and bring to a boil. Once boiled, reduce heat to medium low and simmer for another 10 minutes or so, until the cauliflower and potato are soft.
Once all vegetables are simmering and soft, transfer in batches to the blender and puree the soup, transferring back into another pot. Once transferred, add the half and half until you reach desired creaminess consistency, approximately 1/2 – 3/4 of a cup.
Lastly add most of shredded parmigiano cheese and stir.
Season with Salt and white pepper and reheat on low until bubbling. Serve hot garnished with shredded parmigiano cheese.