Scrape the skin off the burdock root with the back of a knife and make several cuts along its length. Thinly slice it into shavings while rotating it in a bowl of water. Soak for 5 minutes and drain. Slice the carrot diagonally into thin slices, then cut into matchsticks.

Heat a frying pan over medium heat and add the tuna (including the oil). Once it starts bubbling, add the burdock root and carrot. Stir-fry for about 3 minutes until softened.