Scrub roots and scrape skin smooth with a sharp knife under running water. Keep burdock in water to prevent browning. Cut into 2" sections and cut into match sticks. Cut pieces in water.
Heat peanut oil in wok on medium heat. When a bead of water evaporates on contact, add cut burdock and stir-fry for about 5 minutes, or until tender but firm. Add sesame seeds and chili flakes. Continue cooking for another minute, then add sesame seed oil and soy sauce.
Turn off heat and serve.