Prep the Eggplants
Cut off the stems and slice the eggplants in half lengthwise.
Make light diagonal shallow cuts (cross-hatch) on the skin side to help the flavors soak in better.
Microwave
Place the eggplants in a heat-proof bowl and coat them evenly with sesame oil.
Cover loosely with plastic wrap and microwave at 600W for 5 minutes.
Prepare the Sauce
While the eggplant is heating, mix all the ingredients in a separate small bowl.
Marinate
Once the eggplant is done, pour the sauce mixture over it while still hot.
Use "drop-wrap" (place plastic wrap directly onto the surface of the eggplant) and let it sit until it reaches room temperature to absorb the flavors.
Serve
Transfer to a plate and top with bonito flakes and chopped green onions if desired.