1. Preheat oven to 400 degrees Fahrenheit.
2. Line a baking sheet with aluminum foil for easy clean-up and place eggplant onto pan in a single layer.
3. In a small bowl, whisk sesame oil, miso paste, soy sauce, mirin, water, sugar, ginger, garlic, and spicy mayonnaise until combined. Pour over eggplant and toss until all pieces are coated with sauce. Roast for 20 minutes or until lightly browned.
4. Serve warm, sprinkled with scallions and sesame seeds.