Vigorously mix all tempeh marinade ingredients in a mixing bowl. Add the tempeh and toss to coat. Let marinade 15 minutes to an hour.
Mix all the slaw ingredients together and taste for seasoning. Let wilt.
Preheat a large skillet over medium heat. When good and hot, cook mushrooms in canola oil until moisture is released and they’ve browned a bit, about 7 minutes.
Add the tempeh, reserving some marinade. Cook for about 10 minutes, flipping often, until caramelized on the edges.Add more marinade as needed.
Heat tortillas your preferred way and assemble. Slaw on bottom, then tempeh, then tuck in sliced avocado. Sprinkle avo with a little lime juice and salt if you like. Serve asap!