Step 1

Gather all the ingredients. The Japanese short-grain rice-to-water ratio is 1 to 1.1 (or 1.2). I used my Hario GohanGama (donabe rice cooker) in this recipe, but you can use an electric rice cooker (same measurement, and start cooking as usual) or a pot with a heavy bottom (for better heat distribution).

Step 2

Put the rice in a large bowl and add just enough cold tap water to submerge the grains. Discard the water immediately (so the rice doesn't absorb the cloudy water). Next, use your fingers to gently wash the wet grains in a circular motion for 15-20 seconds. Add water to rinse and immediately pour off the cloudy water. Repeat this "wash and rinse" process a couple more times until the water is clear. Drain the rice in a fine-mesh sieve and shake off the excess water. Set aside while you prepare the mushrooms.

Step 3

Cut the king oyster mushrooms into 1½-inch (3.8 cm) lengths. Then, slice the lengths into thin slabs.

Step 4

Cut and discard the bottoms of the shimeji mushrooms and separate the individual mushrooms with your fingers.

Step 5

Discard the stems of the shiitake mushrooms and thinly slice the caps.

Step 6

To your rice pot, add the well-drained rice, dashi, soy sauce, mirin, sake, and salt.

Step 7

Peel and grate the ginger. You will need about ½ tsp per 4 servings.

Step 8

Add the ginger and minced garlic (I use this garlic press). Mix the rice and seasoning mixture well. Gently shake the pot and use your fingers to level the rice so that it's evenly distributed and submerged in the water.

Step 9

Gently place the mushrooms on the rice, arranging the brown shiitake caps and shimeji mushrooms on top so they look pretty when the rice is done cooking. DO NOT MIX. The rice will not cook evenly if mixed with the mushrooms. Cover with the lid and let the rice soak for 20-30 minutes (soaking is crucial for preparing Japanese short-grain rice).

Step 10

For the Hario GohanGama, cook on medium-high heat until it starts to whistle, roughly 10-11 minutes. For a regular donabe or heavy-bottomed pot, cook on medium-high heat for about 13-15 minutes. For an electric rice cooker, choose the Mixed Rice menu, if available; otherwise, start cooking.

Step 11

For the Hario GohanGama, once whistling, cook for another 1-2 minutes and turn off the heat. For a regular donabe or pot, as soon as the rice is done cooking, remove it from the heat. Let the rice steam for 20 minutes for the GohanGama and 10 minutes for the donabe, pot, and electric rice cooker. This resting period is crucial for the rice to steam properly. Resist the urge to peek under the lid and release the steam during this time.

Step 12

Meanwhile, finely chop the chives and transfer them to a small plate. Also, prepare small plates of the sea salt flakes and butter. When the rice is done steaming, add half the butter on top of the mushrooms and quickly close the lid to let it melt with the residual heat.

Step 13

Sprinkle the chives and sea salt flakes on top, and add the other half of the butter (if desired). Gently mix the mushrooms into the rice using a slicing motion to avoid mashing the rice grains. Serve the mushroom rice in individual rice bowls and sprinkle more chives and sea salt on top, if desired.

Step 14

You can keep the leftovers in an airtight container and store in the refrigerator for 2 days and in the freezer for a month.