I love wasabi coleslaw! It's great for adding bite, crunch, and a veg (well, also some mayo) to a meal.
We first had wasabi coleslaw at a Korean restaurant as one of the banchan. When our waitress came by with refills we asked her what it was and she said, "Ummmmmmm...wasabi coleslaw" with "you ninnies" implied. Ha.
This is so wicked easy it barely counts as a recipe.
1 bag coleslaw mix
some rice vinegar
Stir together a spoonful of wasabi powder and a couple spoonfuls of water. You want to make a slurry, not a paste like you would for sushi.
Put the coleslaw mix into a large wide bowl. Add a few blops of mayo (maybe half a cup) and a couple splashes of rice vinegar (maybe a quarter cup) and mix thoroughly with a fork. Add the wasabi slurry and mix some more. At this point I just start tasting and add more of whatever it needs. I like it best with enough mayo and vinegar to moisten the cabbage shreds but not so much that they stick together. Let it sit in the fridge for at least half an hour before serving.