Preheat the oven to 400°F. Line a rimmed baking sheet with aluminum foil or parchment paper. Cut the eggplant down the middle the long way, so you have two long flat halves for each.
Place the eggplant cut side up on the baking sheet. Brush the cut sides of the eggplant lightly with the oil. Roast the eggplant for about 25 minutes, until very tender and lightly browned on the top. Remove the eggplant, and change the oven setting to broil.
Meanwhile, in a small bowl stir together the miso, ginger, sesame oil, soy sauce, vinegar, and pepper. Brush the mixture evenly over the top of the roasted eggplant. Sprinkle over the sesame seeds. Return the baking sheet to the oven and broil for about 4 minutes, until the tops are browned in spots along with the sesame seeds; watch carefully to make sure they don’t get too brown.
Remove from the oven and sprinkle with the scallions (which I forgot to do for these photos). Serve hot or warm.