Preheat your grill or broiler on medium. While you wait, wash 2 eggplants and dry with kitchen paper. Remove the stems and cut them in half lengthways, then score the flesh with a crosshatch pattern.
Once the grill it hot, place the eggplant halves on the wire rack skin side down and grill for 3 minutes to soften the flesh.
Flip them over and grill the skin side for 5 minutes.
While the eggplant is grilling, add the sauce ingredients (2 tbsp yellow miso paste (awase), 2 tbsp sake, ½ tbsp toasted sesame oil, ½ tbsp light brown sugar and 1 tsp mirin) to a small saucepan and bring to a boil over medium-high while stirring continuously. Reduce the heat to low and simmer for a few minutes, stirring occasionally to prevent burning the miso.
Flip the eggplants once more and brush the flesh side with the miso sauce. Grill for 2-3 minutes or until the miso glaze has caramelized.
Sprinkle with toasted white sesame seeds and shredded perilla leaves (shiso). Enjoy!