Wrap each scallop in a slice of pancetta and use the rosemary to skewer the scallops securing the pancetta. Snip off the woody end. Heat the oil in a small saucepan and sizzle the garlic for a minute. Tip in the cannellini beans along with the stock. Bring to a simmer and cook for 3 minutes to warm through. Transfer to a food processor and whiz to purée. Season with a little salt, pepper and a squeeze of lemon. Place a good nonstick frying pan over a medium heat, add the butter and swirl to coat the pan. When it is hot and foaming add the scallops and fry for a couple of minutes each side or until the pancetta is crisp. Remove to warmed serving plates with a spoonful of bean purée. Place the frying pan back over the heat. Add the wine and sizzle until reduced by half, add the chopped parsley and season with a little salt. Drizzle over the scallops and bean purée to serve.
