Peel the lotus root, quarter it lengthwise and slice it. Soak in vinegar water for about 10 minutes.If you don’t like your red peppers too spicy, remove the seeds, then finely chop. (If you’d prefer a spicy dish, don’t remove the seeds!)
Heat the frying pan over medium high and add the sesame oil. Add the dried red pepper and stir fry until fragrant.
Add the lotus root and stir fry until it becomes translucent. Add the sake and stir, then add the mirin and sugar and stir.
Add the soy sauce and reduce to medium heat. Cook until the liquid has evaporated.