Steps

1. Bring a pot of water to a boil. Add soba and cook 4–5 minutes until tender. Drain and rinse under cold water to stop cooking and remove starch; shake off excess water.
2. While the noodles cook, flake the smoked mackerel with a fork into bite-sized pieces, removing any large bones.
3. Cut cucumber into thin matchsticks, julienne the carrot, and slice the spring onion. Toss vegetables lightly with a pinch of salt and let sit for a minute to soften slightly.
4. Make the dressing in a small bowl or a jar: combine soy sauce (15 ml), rice vinegar (15 ml) and a quick drizzle of olive oil (about 5 ml). Season with a little black pepper.
5. In a mixing bowl, combine cooled soba, flaked mackerel, cucumber, carrot and most of the sliced spring onion. Pour the dressing over and toss gently so the fish stays in flakes.
6. Taste and adjust: add a little more rice vinegar for brightness or a touch of salt if needed. Finish with sesame seeds and the remaining spring onion.
7. Serve chilled in a bowl or pack into a takeaway container for travel. (Prep time: ~12–15 minutes.)
8. Hostel Hack: Boil water in a kettle if stove space is limited — pour over noodles in the pot, cover and time 5 minutes; rinse and drain in a large bowl or colander. Use the empty mackerel tin as a small mixing cup for the dressing.