Preheat the oven to 375°F (190°C); 350°F (176°C) if using an air fryer.
Line a baking sheet with parchment paper (optional for easy clean up).
Place the salmon fillets on the parchment skin-side down.
Lightly top the fillets with a big pinch of sea salt and a little freshly ground black pepper.
Whisk the tamari (or soy sauce or coconut aminos), maple syrup, and mustard in a small mixing bowl for the marinade.
Coat the salmon with the sauce, then place it in the oven.
Cook 10-15 minutes until opaque (or use a meat thermometer to cook to 145°F).
Let the salmon cool for 5 to 10 minutes before serving.
