Prepare your enoki beef rolls by warming your vegan meat of choice (ensure that it is a thin, pliable vegan meat). Cut the base of the enoki mushrooms off, so there are no woody bits remaining, then divide the mushroom bunch into 10-12 sections. Wrap one mushroom section with one piece of vegan meat and wrap tightly. Set aside and repeat with remaining mushrooms and meat. If using yuba, wrap each mushroom piece with yuba in a similar manner.
Heat oil in the pan on medium heat until shimmering, then add onion slices and sauté until tender and fragrant. Lower the heat and add your enoki rolls to the pan, laying them flat.
In a small bowl, whisk together dashi. tamari, mirin and sake. Pour this into the pan, over the enoki rolls and bring to a low boil. Cover and let simmer for 5-8 minutes, until the mushrooms are tender.
Finish with black pepper and green onions and enjoy with rice.