Cut the carrot into thin strips and slice the ginger into matchsticks. Cut or tear the mushrooms into bite-sized pieces.

Rinse the rice and drain the water. Add the A ingredients. Pour in the dashi broth until just below the 2-cup line in your rice cooker, and mix lightly. Place the prepared vegetables from step 1 on top and cook the rice.

Finely chop the maitake mushrooms and cut the chicken breast into bite-sized pieces. Place the maitake, chicken, and sake in a resealable bag, massage to combine, and refrigerate for about 30 minutes.

Lightly pat the chicken dry and coat with cornstarch.

Heat a skillet over medium-high heat. Add the chicken and cook, turning, until the surface is white all over.

Reduce to medium-low heat, cover, and cook for about 2 minutes. Flip the chicken, cover again, and cook for another 2 minutes.

Once the chicken is browned all over, add the mixed B ingredients. Simmer until the sauce is almost gone and coats the chicken.

Spoon the cooked mushroom rice into bowls, top with the teriyaki chicken, and serve.