I confess: I have fallen for roasted chestnuts. Here in Porto you can buy them in the street (I have been, every evening). As you walk, you can see the smoke of the roasting carts from far away. You get about 15 chestnuts and the sellers put them in double paper bags (attached to each other) so as you walk in the street and eat these delicious warm nuts, you can throw the shells in the other bag. Really practical.