Place 2 dried shiitake mushroom in a small bowl of 100 ml water and soak for about 20-30 minutes or until softened.
Use this time to cook your rice. (I often use frozen rice and microwave it while cooking the sauce.)
Sauce
Place a saucepan on the stove and 1 tbsp butter over a low heat.
Once melted, add 2 tsp Japanese soy sauce (koikuchi shoyu) and mix.
Add 200 ml chicken bouillon, ½ tbsp light brown sugar and 1 pinch salt. Turn up the heat to medium and bring it to a boil. Pour 1 tbsp cold water into a small bowl and mix in 1 tsp potato starch (katakuriko) to make a slurry.
Let the sauce boil for 1 minute and then add the slurry and ½ tbsp rice vinegar.
Turn the heat down to medium-low and stir continuously until it becomes slightly thickened and glossy. Turn off the heat but leave the pot on the stove and cover to keep it warm.
Omelet
Remove the soaked shiitake mushrooms from the water (but don't throw away the water!), cut off the stems and then cut them into thin slices.
Shred 30 g imitation crab with a fork and finely dice 1 tbsp Japanese leek (naganegi).
Crack 4 egg into a bowl and whisk.
Add the Japanese leek, shiitake mushrooms and imitation crab, then whisk again.
Next add 1 tbsp shiitake mushroom dashi (left over water from soaking the mushrooms) per portion along with 2 tsp Japanese mayonnaise, 1 tsp ginger paste, 1 pinch salt and 1 pinch ground black pepper. Whisk until evenly distributed.
Heat a frying pan (preferably non-stick) on medium-high and once hot, add 1 tbsp cooking oil. Swirl it around and evenly coat the pan. Pour the egg mixture in and whisk for about 30 seconds.
Turn down the heat to medium and continue to heat without mixing until the egg is cooked half way through (it will be a bit runny on top - if you don't like runny eggs you can flip it to cook the other side.)
Make a mountain of 200 g cooked Japanese short-grain rice on a plate and carefully slide the omelet on top of the rice.
Pour the sauce over the top and garnish with 1 tsp toasted sesame oil and a few green peas.
Enjoy!
Notes
If doubling or tripling the recipe, divide the egg and cook each portion separately to ensure beautiful presentation. (This will also prevent the omelette from becoming too thick.)