In a small bowl, whisk together the cornstarch and water until completely smooth.

Add the orange juice, orange zest, soy sauce, brown sugar, minced ginger, garlic, sesame oil, and cornstarch mixture to a small saucepan.

Place the saucepan over medium-low heat and bring the mixture to a gentle simmer. Cook for 3–5 minutes, stirring frequently, until the sauce lightly thickens and develops a glossy consistency.

Remove the orange teriyaki sauce from the heat and transfer it to a clean bowl. Allow it to cool slightly.

Preheat the oven to 400°F (204°C).

Line a baking sheet with foil and lightly grease it with cooking oil. Arrange the salmon fillets on the prepared pan.

Generously brush the salmon with some of the sauce, reserving approximately half in a separate clean portion for finishing and serving.

Bake the Orange Teriyaki Salmon for approximately 12–14 minutes, depending on the thickness of the fillets, until the salmon reaches your preferred safe doneness and flakes easily.

Remove the salmon from the oven and brush the fillets with more of the reserved clean teriyaki sauce.

Switch the oven to broil. Place the salmon under the broiler for approximately 1 minute, watching continuously, until the glaze becomes caramelized and lightly charred around the edges.

Serve immediately over steamed rice. Finish with sesame seeds, red pepper flakes, and chopped green onions, if desired.