01 - In a small saucepan, combine tamari, maple syrup, rice vinegar, sesame oil, garlic, and ginger. Bring to a simmer over medium heat, stirring occasionally.
02 - In a separate small bowl, whisk cornstarch with cold water to form a smooth slurry. Pour the slurry into the simmering sauce while whisking continuously. Cook for about 2 minutes until the sauce thickens enough to coat the back of a spoon. Remove from heat and set aside.
03 - Preheat oven to 400°F. Line a baking tray with parchment paper.
04 - Place salmon fillets skin-side down on the prepared baking tray. Brush each fillet generously with the thickened teriyaki sauce, reserving some for serving.
05 - Bake for 12 to 15 minutes until the salmon is opaque throughout and flakes easily when pressed with a fork.
06 - Transfer salmon to serving plates. Drizzle with reserved teriyaki sauce and garnish with toasted sesame seeds and sliced spring onions.