Preheat your oven or air fryer: Set your oven to 400°F (200°C), or preheat your air fryer to 390°F (200°C).
Make the Glaze: In a small bowl, whisk together the gochujang (or soy sauce substitute), honey, soy sauce, sesame oil, and minced garlic until a rich, glossy sauce forms.
Coat the Salmon: Place the salmon fillets on a lined baking sheet or in the air fryer basket. Generously brush that savory glaze over the top and sides of each fillet.
Cook (with the Onion Twist):
Oven method: Bake for 10–12 minutes until the salmon flakes easily and the glaze is sticky and beautifully caramelized. Pro tip: Scatter the thinly sliced onions right around (and gently over) the salmon during the last 5 minutes of baking so they soften and soak up all that delicious glaze!
Air Fryer method: Cook for 7–9 minutes, adding the sliced onions in the last 3 to 4 minutes.
Serve & Garnish: Sprinkle generously with toasted sesame seeds and fresh green onions. Serve hot over a steaming bowl of rice!