Meanwhile heat 1-2 T. oil in a large heavy skillet until hot. Cook each vegetable in sequence beginning with the potatoes. As each batch is done, drain on paper towels and keep warm. Add more oil as needed. Test potatoes for doneness by probing with fork.
Eggplants are done when batter is tan-brown and zucchini is done when it turns bright green.
This is good with a sauce called yangnyomjang. 1 t. sesame oil 1 T. toasted sesame seeds Mix all ingredients except sesame seeds together in a small bowl. Sprinkle with sesame seeds. Serve sprinkled on chon.