Clean the matsutake mushrooms with a wet cloth and water; trim off any rough parts of the stem; slice lengthwise into 0.5cm slices; trim the bottoms off the shimeji mushrooms.
Add the mushrooms, rice, sake, mirin, soy sauce, dashi and salt to pot; stir to combine the ingredients; let sit for 1hr before cooking.
Cover and bring to boil; then reduce the heat to medium high and simmer gently for 20 min.
Turn off the heat and let the rice steam without opening the lid for another 10 min.
Goes well with teryaki.