Preheat the oven to 375ªF. Cut each eggplant in half lengthwise and use a small spoon to hollow out the eggplant. Just scrape slowly…but keep what you hollow out! You’ll add that to the ground meat mixture.
To the same a large bowl, combine the onion, garlic and ground beef. Heat a large frying pan over medium high heat. When hot, swirl in the cooking oil. Add in the contents of the bowl and saute for 5 minutes or until the beef is no longer pink. Add in the miso paste and cook an additional minute.
Set the eggplant halves on a baking sheet. Spoon the ground beef mixture into each eggplant half. Roast for 20 minutes, or until the eggplant is cooked through. Top with minced basil and serve.