For the Tacos:
- In a medium bowl, whisk together the soy sauce, honey, sesame oil, hot water, garlic, ginger, and black pepper until the honey dissolves.
- Put the steak slices in a large zip-top bag or airtight container and pour in the marinade. Toss around to combine, then seal. Refrigerate for at least 4 hours or overnight for best results.
- Heat a large cast-iron skillet over medium-high heat. Remove the steak slices from the marinade with tongs and put them in the skillet (reserve the marinade); you should hear a strong sizzle. Cook for 2 to 3 minutes until lightly browned on one side, then stir the pieces around and cook for an additional 5 minutes. Reduce the heat to the lowest setting, pourin in the marinade, and let it caramelize for about 1 minute. Remove the pan from the heat.
- Assemble the tacos by placing several slices of steak on each tortilla. Add some shredded cabbage, cilantro, and avocado slices. Drizzle the dressing over the top and serve with lime wedges on the side.
For the Sriracha-Lime Dressing
- In a medium bowl, combine the sour cream, mayonnaise, lime juice, Sriracha, and garlic powder and mix well. Taste and add more Sriracha as desired.
- Use immediately or transfer to an airtight container and refrigerate for up to 5 days.