- 6 red radishes, trimmed, thinly sliced
- 3/4 cup white wine vinegar
- 3 tablespoons sugar
- 1 teaspoon crushed red pepper flakes
- 2 teaspoons kosher salt, divided, plus more
- 1 1/2 cups short-grain sushi rice
- 1 tablespoon dried hijiki (seaweed)
- 1 1/2 pounds large shrimp, peeled, deveined
- 1 medium shallot, finely chopped
- 1/4 cup soy sauce
- 1 tablespoon plus 2 teaspoons gochujang (Korean hot pepper paste)
- 4 teaspoons unseasoned rice vinegar
- 1 tablespoon fish sauce
- 2 teaspoons honey
- 1 teaspoon toasted sesame oil
- 2 cups baby mizuna or arugula
- 2 teaspoons toasted sesame seeds
- Place radishes in a small bowl. Bring white wine vinegar, sugar, red pepper flakes, 1/2 tsp. salt, and 3/4 cup water to a simmer in a small saucepan over medium-high heat and cook, stirring occasionally, until sugar is dissolved, about 5 minutes. Immediately pour brine over radishes and let cool. Cover and chill at least 2 hours.
- Meanwhile, rinse rice until water runs clear (this removes surface starch and keeps rice from getting gummy). Combine rice and 1 1/2 cups water in a medium saucepan, season with 1 1/2 tsp. salt and let sit 30 minutes.
- Bring rice to a boil. Reduce heat to low, cover, and cook until rice is tender, 18–22 minutes. Remove from heat and let sit (still covered) 10 minutes, then fluff with a fork; keep warm.
- Soak hijiki in 1/2 cup cold water in a small bowl until softened, 10–12 minutes. Drain; set aside.
- Bring a medium pot of water to a boil; season generously with salt. Add shrimp, cover pot, and remove from heat. Let sit until shrimp are cooked through, about 3 minutes. Drain and transfer shrimp to a bowl of ice water; let cool. Drain and pat dry; cut into 1/2″ pieces. Set aside.
- Whisk shallot, soy sauce, gochujang, rice vinegar, fish sauce, honey, and oil in a large bowl. Add reserved hijiki and shrimp to honey-gochujang dressing; toss to coat. Cover; chill 1 hour. Taste and season with more salt if needed.
- Divide rice among bowls and top with shrimp mixture, drained pickled radishes, and mizuna. Sprinkle with sesame seeds.
- Radishes can be pickled 5 days ahead; keep chilled. Shrimp can be cooked 8 hours ahead; cover and chill.