Cheese soups are especially savory and this one is made even more delicious with the addition of the smoky flavor of bacon.
Heat the butter in a large saucepan over medium heat until the foam subsides. Add the leek, mushrooms and cauliflower. Cover and cook, stirring often for 5 minutes. Add the stock and and bring to the boil. Lower the heat, cover and simmer for 10 minutes. Transfer the mixture to a food proccesor. Add the cheddar cheese and puree for 1 minute, or until smooth. Serve immediately with the crumbed bacon on top.