Cut the eggplant, the potato and the peppers into pieces. Chop finely the scallion, the ginger and the garlic. Blend the starch, the light soy sauce, the sugar, the salt with a little water and make the flavoring sauce. Heat the vegetable oil in a frying pan. Fry the potato until the surface turns gold. Fry the eggplant until it begins to contract. Fry the pepper slightly. Leave a little remaining oil in the pan and remove the rest. Heat the oil and sauté the scallion, the ginger and the garlic until there is aroma. Add the fried potato and eggplant, stir. Add the flavoring sauce. Add the peppers and sauté until the sauce becomes sticky. Add the sesame oil and finish.