In a small bowl, whisk together sesame oil, ginger, and scallions. Add rice vinegar and a pinch of salt and pepper, adjusting to taste. Set aside.

Bring a large pot of salted water to a boil. Cook soba noodles according to package instructions, usually around 5–7 minutes. Drain and rinse under cold water.

Julienne the cucumber using a peeler or spiralizer, or cut into matchstick-sized pieces.

In the pot with the cooled soba, add julienned cucumber and cilantro. Drizzle with 3/4 of the dressing and toss gently.

Serve the salad on a plate, drizzling with the remaining dressing and seasoning with salt, pepper, and lime juice to taste.