Mix the scallion, peppercorn, dried red pepper, soy sauce, wine, salt, and sugar in a mixing bowl.
Stir well to dissolve the salt and sugar.
Set aside.
Cut the spareribs between each rib.
Wash and drain.
Add to the bowl with the marinade and let stand for 20 to 30 minutes.
Turn and mix several times when marinating.
Coat each sparerib with the spicy rice powder.
Arrange with shredded scallion in a bamboo steamer lined with some bok choy leaves, making 2 layers at the most.
Pour the extra marinade on top.
Steam over medium high heat for 1 1/2 hours.
Check after 1 hour of steaming; if some spicy rice powder coating the ribs is still dry, turn meat around and continue steaming until all the rice powder coating is moist, up to another half hour.