Heat olive oil in a large saucepan. Add in the onion, crushed garlic and half of a the cubed pancetta, cook for roughly 5 minutes or until softened.
Whack in the cubed potato, beans, chestnuts, rosemary, stock, milk . Bring to a simmer then cover and leave it to cook until the potato has softened.
While this is simmering, fry up the remaining pancetta for roughly 5 minutes until crisp. Place to one side.
Remove the rosemary sprigs then puree the soup, taste for seasoning. Ladle into beautiful bowls then scatter with the crispy pancetta, picked rosemary and freshly milled black pepper.
Beautiful for lunch, dinner, supper with a hunk of warm crusty bread or a heart warming mug of deliciousness....