Place the salmon in a gallon-size resealable plastic food storage bag. In a small bowl, combine the green onion, cilantro, sugar, ginger, garlic, crushed red pepper, rice vinegar, soy sauce, sesame oil, and 6 tablespoons of the vegetable oil. Whisk together and pour over the salmon. Close the bag and refrigerate for at least 2 and up to 4 hours, turning the bag at least once to ensure even marination. Remove the fillets from the marinade (discard the marinade) and keep them, covered, in the refrigerator until ready to cook or up to overnight.

Heat a medium skillet over medium heat. If you’re using the King’s Hawaiian rolls, leave each 4-pack intact and slice them in half horizontally (each 4-pack makes 1 large sandwich). Lightly brush the cut sides of the rolls with 2 tablespoons vegetable oil. Working in batches, add the rolls to the skillet, oiled side down, and cook until toasted. Set aside.

Season the salmon with salt and pepper. Raise the heat under the skillet to high, and add 1 tablespoon vegetable oil to the skillet. Working in batches, add the fillets and cook, turning them once, until golden brown on both sides, about 5 minutes for medium, depending on the thickness of the fillets. Add the final 1 tablespoon of oil as needed. Set aside.

Combine the watercress and red onion in a small bowl, and drizzle with the extra virgin olive oil. Season lightly with salt and pepper, and toss to combine.

To assemble: Spread Soy Mayo on both halves of the rolls. Add the watercress salad to the bottom halves, and then the salmon fillets. Drain the liquid from the Gingered Radish Pickle, and lay the pickles on top of the salmon fillets. Top with the top halves of the rolls.

For the Gingered Radish Pickle

Combine the radish and jalapeño in a small bowl. In a small saucepan, combine the rice vinegar, mirin, ginger, sugar, and salt. Bring the mixture to a boil, and then pour it over the radishes and jalapeño. Set aside until cooled. Cover, and refrigerate up to several days until ready to use.