Cook rice with about 2 cups of water on a simmer for 12 minutes.
In the meantime cut off the ends of the Chinese broccoli. Line up with the stems facing same direction on a cutting board. Cut the stalks and the leaves in two parts.
Add about 1 inch of water to a wok or large pan and bring to a simmer on medium. Place the broccoli stems at the bottom and layer the leaves on top of the stems. This will ensure the two parts cook more evenly in the same amount of time. Steam for 3 to 6 minute, or until the stems are easily pierced with a fork. Use tongs to lift the leaves to a plate.
Fluff rice with a fork and leave to rest 5 minutes covered.
Pour off any remaining water from wok and wipe dry. Add the oil, ginger, garlic and chile pepper, then turn heat to med-low. Stir in the miso, water, sesame oil and soy sauce. Cook for 15 seconds. Pour sauce over the Chinese broccoli and toss if desired.
Plate rice in 3 to 4 bowls, and per bowl add some Chinese broccoli on top, a big handful bonito flakes, and shiso leaves if desired.