Rinse the rice until the water runs mostly clear. Drain well in a colander and set aside.
Pour boiling water over both sides of the abura-age to remove excess oil. Pat dry and cut into thin strips.
Peel the gobo and carrot and cut into thin strips. Trim the base of the shimeji mushrooms and separate by hand.
Cut the chicken into bite-sized pieces, about ½ inch.
In a pot, add the drained rice, dashi broth, light soy sauce, mirin, sake, and sea salt. Gently place the chicken, abura-age, mushrooms, gobo, and carrot on top without mixing. Cover with a lid.
If time allows, let the rice rest for about 15 minutes before cooking.
Cook over medium-high heat until boiling, then reduce to low and cook for 12 minutes. Do not open the lid.
Turn off the heat and let steam, covered, for 10–15 minutes. Gently fluff before serving.