Add the butter and the chestnuts to the pancetta saucepan and with a wooden spoon or spatula, press down on them to break them up into pieces. Once the chestnuts have been warmed through, turn the heat up and add the Marsala to the pan. Cook until the mixture has reduced and thickened slightly.
05Add the sprouts and half the parsley to the saucepan and mix well. Season the Brussels sprouts with freshly ground black pepper.06To serve, place the Brussels sprouts onto a warmed serving plate and sprinkle the remaining chopped parsley over the top.