01 - Preheat oven to 400°F. Line a baking sheet with parchment paper and set aside.
02 - In a small saucepan, whisk together tamari, maple syrup, rice vinegar, sesame oil, minced garlic, and grated ginger. Place over medium heat and bring to a gentle simmer.
03 - Dissolve cornstarch in water in a small bowl, then stir the slurry into the saucepan. Continue cooking for 2-3 minutes, stirring constantly, until the sauce thickens to a glossy glaze. Remove from heat.
04 - Arrange salmon fillets on the prepared baking sheet, skin side down. Brush generously and evenly with the teriyaki sauce, reserving a small amount for finishing.
05 - Bake for 12-15 minutes, or until the salmon is just cooked through and flakes easily when tested with a fork.
06 - Remove from oven and brush the salmon with any remaining sauce. Sprinkle with sesame seeds and sliced spring onions before serving.