1.Preheat oven to 180°C. Line an oven tray with baking paper.
2.Cut eggplants in half lengthways. Score a 5mm border with a small knife. Spoon out flesh leaving a shell. Coarsely chop flesh. Place eggplant shells on tray.
3.Heat oil in a non-stick large frying pan over high heat; cook chopped eggplant, walnuts, rice, green onion and garlic, stirring, for 5 minutes or until eggplant is tender. Add miso, sauce and mirin; cook, stirring, for 30 seconds or until eggplant is coated. Spoon mixture into eggplant shells.
4.Roast filled eggplant for 25 minutes or until golden and tender.
5.Meanwhile make radish salad: Place ingredients in a medium bowl; toss gently to combine.
6.Serve filled eggplant topped with radish salad.
You can fill eggplants ahead of time; store, covered in the refrigerator until required. Roast just before serving.Note