1. Soak Dictyophora (bamboo fungus) in water for 8-10 hours in advance, changing the water once.
2. Cool the steamed rice until it is no longer hot to the touch; mix about 40 ml of sushi vinegar into approximately 640 g of rice.
3. Add a small amount of salt, vinegar, and sesame oil to the soaked Dictyophora and mix well; set aside. Blanch broccoli and carrots in advance; after blanching, chop the broccoli florets finely.
4. For an outside-out roll: first lay half a sheet of nori, spread a layer of rice over the entire nori, then cover with a layer of plastic wrap. Holding the plastic wrap and nori together, flip them over so the plastic wrap is on the bottom and the nori is on top.
5. Place carrot strips, cucumber strips, and Dictyophora on top. While rolling, pull the sushi mat and plastic wrap forward; do not roll them into the sushi.
6. The completed roll.
7. Finely chop the Dictyophora or spread the chopped broccoli on a large plate, then roll the outside-out sushi roll over it to coat.
8. For an inside-out roll: spread a layer of rice on the nori, place carrots, cucumber, chopped broccoli, and Dictyophora on top, and roll it up. When eating, dip in soy sauce and wasabi.