Steam the sprouts for 4-5 minutes, depending on their size, until just tender. Drain thoroughly. Lay the pancetta out over the base of a large, nonstick frying pan and place over a medium heat. As the pancetta melts and turns golden underneath, scatter with the sugar and, using tongs, turn the rashers over. Cook until deeply burnished and crisp. Remove to a bowl.
Tip the chestnuts and sprouts into the pan and stir thoroughly. Season with black pepper. Return the pancetta to the pan, then spoon into a warmed dish.
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.