Salmon Teriyaki Onigiri

Bring 2 cups short-grain sushi rice, rinsed until water runs clear, and 2½ cups water to a boil in a medium saucepan, stirring occasionally. Reduce heat to low, cover pan, and cook until water is absorbed, 12–14 minutes. Remove from heat and let sit (still covered) 15 minutes. Gently fluff rice with a fork, cover again, and let sit until ready to use.

Meanwhile, pat one 8-oz. skin-on salmon fillet (about 1" thick) dry and season with kosher salt on both sides. Sift 1 Tbsp. potato starch or cornstarch through a fine-mesh sieve over salmon, turning to coat both sides. Stir 1 Tbsp. plus 2 tsp. soy sauce or tamari, 1 Tbsp. dark brown sugar, 1 Tbsp. mirin, and 1 Tbsp. cooking sake in a small bowl to combine.

Heat 1 Tbsp. vegetable oil in a medium heavy skillet over medium-high. Cook salmon, skin side down, gently pressing down on fish with a spatula, until skin is golden brown, about 5 minutes. Turn over and cook until flesh side is browned, about 4 minutes. Add a splash of cooking sake, cover pan, and cook 3 minutes. Uncover and add soy sauce mixture. Cook, basting salmon continuously with sauce, just until sauce is thickened and coats fish and salmon is opaque throughout, about 2 minutes. Remove from heat. Transfer salmon to a plate, leaving sauce behind; let sit until cool enough to handle.