Courtesy of Chef Curtis Luk of The Parker Restaurant.
Black Tea Dashi
In a pot, add a couple tablespoons of oil. Cook the ginger for one minute over medium heat. Add mushrooms and continue cooking until the mushrooms are tender and shrink to about half.
Add all the rest of the ingredients and cook until well combined and with the texture of a dry paste. Set aside.
In a pot bring water to a boil. Turn off the heat, add kombu and allow to steep for 15 minutes.
Turn the heat back on and just before it boils remove the kombu and discard.
Add the rest of the ingredients (except for potato starch). Turn off the heat again and allow to steep for 10 minutes.
Strain out the tea and return the pot of stock to the stove. Bring the dashi to a boil and whisk in the potato starch slurry. Allow to boil for 30 seconds then remove from heat.
In some bowls, place the rice in a line in the centre. Going from one side to the other place king oyster disks, shimeiji mushrooms, spinach, egg, and relish. Pour black tea dashi around the rice. Garnish with scallions. Serve.