Preheat your grill or oven to 400°F (200°C). If using a grill, lightly oil the grates to prevent sticking.
In a small bowl, combine the teriyaki sauce, olive oil, grated ginger, and minced garlic. Mix well.
Season the salmon fillets with salt and pepper on both sides.
Place the salmon fillets in a shallow dish and pour the teriyaki mixture over them, ensuring they are well coated. Let marinate for 15-30 minutes for enhanced flavor.
If grilling, place the salmon skin-side down on the grill and cook for about 6-8 minutes per side, or until the salmon flakes easily with a fork. If baking, place the fillets on a lined baking sheet and bake for 12-15 minutes.
In the last few minutes of cooking, sprinkle the diced mango over the salmon to warm it through.
Once cooked, remove the salmon from the grill or oven and let it rest for a couple of minutes. Garnish with sliced green onions before serving.