Step 1 In a medium bowl, soak the brown rice in enough water to cover for at least 2 hours, up to overnight.
Step 2 Wash the short-grain rice well using a colander or strainer. Set aside for 15 minutes to drain completely.
Step 3Drain the brown rice and place in the donabe or electric rice cooker with the rinsed short-grain rice and the measured water to soak for 20 minutes.
Step 4Meanwhile, bring a large pot of salted water to boil. Blanch the dandelion greens just until wilted and bright green, about 30 seconds. Drain well, squeezing out any excess moisture, and finely chop. Set aside.
Step 5While the rice is cooking, heat a medium saute pan over medium heat. Add the sesame oil, then the chicken, and fry until the chicken is crumbly and loose, 5 to 6 minutes. Stir in the dashi, soy sauce, sake, mirin, sugar and grated ginger and simmer until most of the liquid is absorbed, about 15 minutes, stirring frequently. Remove from heat and set aside in a warm place.
Step 6When the rice has rested, remove the lid. Fold in the chopped greens, gently scooping rice from the bottom of the cooker using a paddle or spatula. Season to taste with salt if desired.
Step 7Mound the rice in a serving bowl and top with the warm chicken. Garnish with the topping(s) of your choice. Serve immediately.