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.