In a small bowl, whisk together soy sauce, honey or maple syrup, rice vinegar, sesame oil, grated ginger, and minced garlic to make the teriyaki sauce.

Place the salmon fillets in a shallow dish or a ziplock bag. Pour half of the teriyaki sauce over the salmon, reserving the other half for later. Let the salmon marinate in the sauce for at least 15 minutes or up to 1 hour in the refrigerator.

Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper or lightly grease it.

Remove the salmon from the marinade and place it on the prepared baking sheet. Discard the used marinade.

Bake the salmon in the preheated oven for about 12-15 minutes, or until it is cooked through and flakes easily with a fork. The cooking time may vary depending on the thickness of the fillets.

While the salmon is baking, transfer the reserved teriyaki sauce to a small saucepan. In a separate small bowl, whisk together cornstarch and water to make a slurry. Add the slurry to the saucepan.

Place the saucepan over medium heat and cook the sauce until it thickens and becomes glossy, stirring frequently. This should take about 2-3 minutes. Remove from heat.

Once the salmon is cooked, remove it from the oven and brush it with the thickened teriyaki sauce. Reserve some sauce for serving.

Garnish the salmon with sesame seeds and sliced green onions.

Serve the baked teriyaki salmon hot with steamed rice and your choice of steamed vegetables.