Add the oil and butter to a heavy frying pan and fry the onion and bacon until sizzling. Add in the cauliflower, potatoes and carrots and continue to cook on a low heat until softened.

Add in the fresh thyme, then stir in the chicken stock. Bring to a boil, then simmer until all the vegetables are tender. Add the cheese and cream, then blend with a stick blender until very smooth. Season to taste.

To make the caramelized walnuts, heat the sugar and water until it forms a thick syrup, then coat the walnuts with the syrup and allow to cool on a non-stick baking sheet.