Cà Tím Nướng Mỡ hành ( Grilled Eggplant With Scallion Oil )

2 medium Eggplants or 1 big one1 Table Spoon scallion oil ( chop spring onion or scallion , put in hot pan with 1 table spoon of oil, fry for 20 seconds, pour into a bowl )2 Table Spoon soy sauce ( or make your own soy sauce with chilly, garlic, sugar, lime and soy sauce to own taste )salt and pepperPoke around the eggplants with toothpick and soak in salt water for 30 minutes (this is optional,