To prepare the beef, combine the beef, soy sauce, honey, garlic, sesame oil, and sesame seeds in a small bowl. Cover and refrigerate until ready to use. When ready to use, cook in a skillet or a wok with one tablespoon of oil over medium-high heat, until cooked through.
Doraji: Drain the bellflower root. Toss with 1 tablespoon salt, then rub the bellflower for a minute to wilt it slightly and release some of its bitterness. Transfer to a sieve and rinse well to remove the salt, then drain thoroughly. Heat the vegetable oil in a small skillet over high heat. Turn down the heat to medium, add the bellflower root, stirring, and cook until wilted and softened, about 3 minutes. Transfer to the platter.
Gosari: Cut the fernbrake into 2-inch lengths. Heat the vegetable oil in a small skillet over medium-high heat. Add the fernbrake and cook, stirring, until softened, 3 to 5 minutes. Add the soy sauce, sugar, garlic, and sesame oil and cook, stirring, for 1 minute. Transfer to the platter.
Gaji namul: (Traditional preparation) Wash and cut the eggplant, cut in quarters lengthwise, then cut into 1-inch pieces. Put the eggplant in a steamer basket set over boiling water and steam until fork-tender, 5 to 10 minutes. Transfer to a plate and set aside. Add the scallions, garlic, soy sauce, sesame oil, sugar, gochugaru, sesame seeds, and salt, and season with pepper. Cool to room temperature before serving.For a non-traditional, alternative preparation method (my favorite), see note 3.