It's possible to prepare this sushi house staple easily in your home kitchen. Just soak strips of seaweed in water. Then, dry them and toss the seaweed with toasted sesame seeds and a little rice wine vinegar. Tomatoes are called for as garnish, though you can leave them out if you'd like. When serving this salad with sashimi, you can omit the vinegar. Dress the dish shortly before serving so it retains its texture.