For the slaw: In a bowl, blend the vinegar and wasabi, and then add the cabbage and onions. Allow this mixture to marinate, or soak, for 30 minutes or up to 1 hour. This marinating will soften the cabbage and onions without cooking, thus preserving the nutrients of the vegetables. Once marinated, we will hold the slaw until building the tacos.
For the dressing: Slice the avocado in half, remove the seed and scoop the "meat" of the avocado into a small mixing bowl. Next, with a spoon, mash the avocado until smooth. Add the sambal, tomato, cilantro and salt to taste. Mix well, then cover and hold until serving.
For the bison: Warm the pulled meat with the stock in a saucepan over medium-high heat until warmed. Once warm, remove from the heat, discard any remaining liquid and keep the meat warm to build the tacos. Construction: Drain the cabbage from the marinade and add 1 tablespoon slaw to each tortilla. Then add the bison and finish with 1 tablespoon tomato avocado dressing.