You can just use the bean sprouts as-is if you like, but if you take the thin roots off they'll look better and have a better texture too.
Rinse the bean sprouts, and boil for 1 minute. Drain.
Drain off the water. Transfer to a bowl and mix with all the flavoring ingredients while still hot. Finished!
Try it on top of ramen!
Story Behind this Recipe
I wanted to eat delicious ramen, so I made this to use as a topping.
If you cook the bean sprouts for just one minute, they'll be nice and crispy. Adjust the amount of doubanjiang to taste. I wrote about this on my blog too (in Japanese): http://ameblo.jp/cooking-s-papa/entry-11620193084.html.