To cut the mock eel

1. Gently squeeze the reconstituted shiitake to get rid of extra moisture, then cut into long, thin strips, stopping when you reach the tough center. Discard that inedible portion. You can alternatively cut off the tough center and cut the shiitakes into smaller slices.
2. Bring several inches of oil in a heavy pot to 350 degrees over medium to medium-high heat. I use a 2-quart Lodge Dutch Oven. You can use a deep fry or candy thermometer to register the correct temperature, but I just insert a wooden chopstick into the hot oil so it touches the bottom. If bubbles form around the chopstick immediately I’m ready to fry. (It typically takes 5-7 minutes for the heat to come to this point.)
3. Place the cornstarch into a medium-sized bowl. Place 1/4 to 1/3 of the cut or sliced shiitakes into the cornstarch, using your hands to coat. Tap off any extra and place into the hot oil. Work in small batches or your eel will get soggy.
4. Once golden, transfer the mock eel to paper towels to drain while you finish frying the rest.

To make the sauce

1. Heat the oil over medium heat in a medium-sized saucepan. Add in the ginger and stir constantly for about a minute, adding in a little splash of water if the ginger starts turning golden.
2. Add in the scallions and stir constantly for a minute more, or until most of the moisture is gone from the saucepan. Deglaze with the mirin, and allow to sizzle for a few seconds, then add in the rest of the ingredients. Stir until slightly thickened, then remove from the heat.
3. Toss in the fried mock eel until well coated. Transfer to two serving bowls, reserving any leftover sauce to serve on the side. Garnish as desired with the reserved scallions, sesame seeds, spice and cooked rice.