Mix soy sauce, rice vinegar, gochujang chili flakes, and sesame seeds in a bowl.
Thinly cut bell pepper, carrots, potato, scallions, and zucchini. Slice the mushrooms and finely chop the green chili. Combine all in a bowl.
Add all-purpose flour, rice flour, salt, pepper, and water. Mix it with a wooden spoon. Batter should be thick and should coat the vegetables.
Heat a pan then add 1 tablespoon oil to coat the surface of the pan. Once hot, scoop a generous amount of the veggie mixture.