Rinse the dried seaweed thoroughly under cold water to remove any impurities. Place it in a bowl and cover it with at least five times its volume of water. Allow it to soak for about 10 minutes, or until the seaweed is fully rehydrated and tender.

In the meantime, prepare the dressing by combining the sesame seed oil, soy sauce, rice vinegar, mirin, cayenne pepper, grated ginger, and finely chopped shallot in a salad bowl. Mix well to create a balanced and flavorful dressing.

Once the seaweed is rehydrated, drain it thoroughly and gently squeeze out any excess water. Use kitchen scissors or a knife to chop the seaweed into manageable pieces, depending on your desired size.

Add the chopped seaweed to the salad bowl with the dressing. Toss gently to ensure the seaweed is evenly coated with the flavorful mixture. Taste and adjust the seasoning as needed to achieve your preferred balance of flavors.

For a finishing touch, sprinkle the optional sesame seeds over the salad for added texture and a nutty aroma. Serve immediately and enjoy this refreshing, nutrient-packed dish.