Put the shreds into a basin filled with cold water to soak.
Cut the green pepper into shreds.
Cut the green onion and ginger into chopped pieces.
Place a wok over a high heat until hot. Add some cooking oil, swirling to coat sides. Add in the red chili shreds, chopped ginger and green onion to fry over a high heat until fragrant, about 20 seconds.
Pour in the potato and green pepper shreds, add in some white vinegar, stir-fry it for about 2 minutes on a high heat until it is 90% cooked.