Place the dried wakame and hijiki in separate small bowls and cover each with cold water. Let soak 5–10 minutes until softened. Drain thoroughly in a fine-mesh sieve and gently squeeze out excess water. Chop larger wakame pieces into bite-sized pieces if necessary.

Prepare vegetables: thinly slice cucumber (remove seeds if watery), julienne carrot, and thinly slice green onions. If using microgreens or shredded lettuce, rinse and dry well.

Combine: In a medium mixing bowl, add the rehydrated wakame and hijiki, cucumber, carrot, green onions, and microgreens/lettuce if using. Toss gently to combine and set aside while you make the dressing so the flavors can begin to mingle.

Dressing

Make the dressing

In a small bowl or jar, whisk together rice vinegar, soy sauce, toasted sesame oil, mirin (or honey), sugar, grated ginger, minced garlic, and red pepper flakes until sugar dissolves. Add 1 tablespoon water to loosen the dressing; adjust thickness to your preference. Taste and balance acidity/salt/sweet: add more soy for salt, more vinegar for brightness, or a touch more honey for sweetness.

If you prefer a smoother emulsion, shake the ingredients vigorously in a jar with a tight lid or whisk with a small spoon for 30 seconds.

Assembly & Finish

Dress the salad: Pour the dressing over the seaweed and vegetables. Start with about two-thirds of the dressing, toss gently to coat, and let sit 2–3 minutes for flavors to meld. Taste and add remaining dressing as needed.

Season and garnish: Sprinkle 1 tablespoon toasted sesame seeds into the salad and add salt to taste (start with 1/4 tsp). If using, add the fresh lime juice and final drizzle of toasted sesame oil. Toss once more gently to combine.

Serve: Transfer to a serving bowl or individual plates, sprinkle with the remaining 1/2 tablespoon toasted sesame seeds for presentation, and serve chilled or at cool room temperature. Leftovers keep well covered in the refrigerator for 2–3 days; drain excess liquid before serving.