In a large pot fitted with a steamer basket, bring 1 inch of water to a boil. Add eggplant, cover and reduce heat to medium. Steam eggplant until tender, about 10 minutes. In a bowl, whisk hoisin, garlic, ginger and 1 tbsp. water. Add eggplant to bowl and gently toss to coat. Transfer to a plate and garnish with scallions.