Brush 1 tablespoon of the oil on the octopus (reserving the rest), season with salt and pepper, and add to a pot with enough water to cover. Simmer until the octopus is cooked through, about 20 minutes.
In a medium bowl combine the remaining sesame oil with soy sauce, cucumber, scallions, chile, nori and salt.
Remove octopus to a utility plate to drain and set aside until cool enough to handle. Remove the octopus head and legs, split in half, then slice and dice small.