Prep work: Preheat the oven to 400°F. Line a 9x13-inch pan with parchment paper. Alternatively, you can coat it with non-stick spray. Arrange the four 6 ounce salmon fillets in the pan so that they are close but not touching, skin side down.
Make cornstarch slurry: In a small bowl, whisk together the 1 tablespoon water and 1 tablespoon corn starch.
Combine sauce ingredients: In a small saucepan, whisk together the 1/4 cup brown sugar, 1/2 cup soy sauce, 2 tablespoon lemon juice, 2 cloves garlic, 1 teaspoon fresh ginger, and 1 teaspoon toasted sesame oil. Slowly whisk in cornstarch slurry into the mixture.
Cook the sauce: Heat the teriyaki sauce over medium-high heat until it comes to a boil. Reduce heat until it can maintain a gentle boil and allow to cook for about 2 minutes until the mixture just starts to thicken. Remove from heat.
Bake salmon: Remove about 3 tablespoons of the sauce and reserve for later. Pour or brush the remaining sauce over the salmon fillets. Bake in preheated oven for 12-16 minutes or until salmon is flaky and cooked through. Bake times may vary by the thickness and initial temperature of salmon. Salmon is considered cooked when the thickest part reaches 145°F when checked with an instant-read thermometer.
To serve: Brush the top of the salmon with the reserved sauce. Garnish with 4 scallions and 1 teaspoon sesame seeds. Serve with rice and a steamed vegetable.
Notes
Use wild-caught salmon like sockeye or coho for the best flavor.
Adjust baking time based on thickness of the salmon.
Broil the salmon briefly at the end for crispy, caramelized edges.
Leftovers keep in the fridge up to 4 days. Reheat gently or enjoy cold.