Cut the tofu sheets into medium rectangles or squares (about 10×15 cm).
Bring water to a boil and briefly simmer the tofu sheets for 1–2 minutes to soften them. Drain and pat dry.
Thinly slice the onion into strips.
Rinse and trim the enoki mushrooms (if you use them). Trim cilantro.
Place a bit of onion, mushrooms, and cilantro in the center of each tofu rectangle. Roll them up tightly like spring rolls. You can secure the rolls with a toothpick or leave them as is.
Place the rolls on a hot pan or grill, and cook until golden and slightly crispy —about 2–3 minutes per side.
Prepare BBQ-Oil: Mix vegetable oil, Chinese BBQ seasoning, and oyster sauce.
Sprinkle generously with BBQ-oil mix and black sesame seeds. Serve hot.