Seaweed is a wonderful side dish in a Japanese meal - slight, delicate, usually with the subtlest taste of the sea. But there are many kinds of seaweed out there. For this salad, I strongly urge you to acquire one remarkably springy, frilly, fresh-tasting green seaweed imported from Japan.

• 1 (500-gram) bag salted tosaka ao, or about 3 very loosely packed cups of another seaweed (see Cook's Note)
• 1 tablespoon rice wine vinegar
• 2 teaspoons fresh lemon juice
• 1/2 teaspoon kosher salt
• 1 teaspoon sugar
• 1/2 teaspoon finely grated fresh ginger
• 1-1/2 teaspoons Japanese soy sauce
• 4 teaspoons Japanese or Chinese sesame oil
• 1 tablespoon sesame seeds, toasted until golden brown in a hot skillet

Rinse the seaweed in a large bowl in three or four changes of cold water, swishing it around to release the salt. Cover with water and set it aside to soak for 10 minutes. Drain, and then thoroughly squeeze the seaweed between clean kitchen towels to remove all excess moisture. Return to a dry mixing bowl.

Prepare the dressing: Whisk the vinegar, lemon juice, salt, and sugar together in a bowl until the crystals dissolve. Add the ginger, soy sauce, and sesame oil, whisking to incorporate.

When ready to serve, toss the seaweed with most of the dressing and half of the sesame seeds. Taste and add more dressing to suit your taste. Divide among six small salad bowls, sprinkle each portion of seaweed with the remaining sesame seeds, and serve immediately.

Cook's Note: I am crazy about green (ao) tosaka seaweed, prepared by the Kaneryo company, exported from Tokyo by the Central Trading Company. It is heavily salted, packed in a plastic bag, and sent to the U.S. frozen. I buy mine at the great Japanese store Katagiri in New York City, where it's on the refrigerator shelf already defrosted. If you buy it, you can store it, defrosted, in your refrigerator for a couple of weeks.