Cut eggplant longways into 1 1/2 cm thick slices. Soak in a bowl of water to prevent discoloration.
Wipe any excess moisture off of the eggplant. Put some vegetable oil on the cut surface and put some salt and black pepper. Grill eggplant slices in a grilling pan or under an oven grill.
Sautee pork slices in a frying pan over mid-high heat. Use a piece of paper towel to wipe any excess oil from the pan.
Mix the soy sauce, sugar and sake to make teriyaki sauce and pour it into the frying pan. Make sure the pork slices get all the teriyaki sauce. Take them out and put aside.
In the same frying pan put the eggplant slices. Let them soak in the teriyaki sauce.
Put the eggplant slices on a plate topped with pork slice. Scatter minced scallions all over them.