Soak mushrooms in hot water and slice when cooled. Keep the soaking liquid.
Cut the chicken fillets into bite size pieves and marinade in the mirin and soya sauce for at least 30 minutes.
Wash the rice and set aside.
I cooked this in a rice cooker but you can use a stove top pot just as easily.
Place washed rice, garlic, ginger, chicken and mushrooms in the pot. Top up with the soaking liquid using the dashi stock. Ensure that the rice and chicken is just covered with liquid. (About 1 cm above the ingredients.)
Turn on the rice cooker and let it cook like normal.
If doing this in a pot, bring the pot to boiling point, then turn it down to a simmer and cover with a lid. Cook until the liquid evaporates. Check frequently but don't stir. You might need a bit more liquid that in a rice cooker.
To serve, dish out onto a bowl, sprinkle on some sliced spring onions and a sprinkle of the very aromatic Schichimi pepper.
You can serve this with a bowl of miso soup on the side and some pickles if you have any.