Peel the cucumber and cut the ends off. Slice cucumber in half lengthwise and remove the seeds. Using the julienne blade on a mandoline, run the cucumbers lengthwise to form noodles. If you find it difficult to work with the whole cucumber, cut the length in half to make it easier to handle.

In a dry skillet toast the sesame seeds until lightly golden. Allow to cool.

In a small bowl whisk together soy sauce and sesame oil.

Place cucumber noodles in a serving bowl and toss with soy sauce, sesame oil, and a teaspoon of the mixed toasted seeds.

Top with remaining toasted sesame seeds. Sprinkle with red pepper flake if desired.

Serve cold.