Slice the octopus very thinly.
Alternately peel a ½-inch-side strip lengthwise, leaving a strip of the skin intact. With this method, the cucumber slices have some decorative dark green accents and a little bit of extra crunchiness. Cut the cucumber into small pieces (I use Japanese cutting Technique called “ Rangiri”)
In a small bowl, soak the dried seaweed in warm water. Let it soak for 15 minutes. Drain and squeeze liquid out. Set aside.
In a medium bowl, combine all the ingredients for Vinaigrette.
Add the cucumber, octopus, seaweed, and sesame seeds and toss all together.
Chill in the refrigerator for 15-30 minutes and ready to serve.