2 cups sushi rice
3 tablespoons white miso
2 tablespoons honey
1 tablespoon vegetable oil
1 tablespoon freshly grated ginger
2 teaspoons fresh grapefruit zest plus 1 tablespoon juice
4 (6- to 8-ounce) skinless salmon fillets, patted dry
Salt and pepper
4 scallions, thinly sliced
1 tablespoon unsalted butter, cubed
Any combination of kimchi, chile crisp, toasted nori sheets, and sliced cucumber, avocado or radish, for serving