Preheat the oven to 400°F and line a baking tray with parchment paper.
Pat the fish dry with a paper towel and divide the fillet into three uniform portions.
Sprinkle salt and pepper on the skin, and lay it skin-side down on the parchment-lined baking tray.
Combine the mustard and chives in a small bowl.
Spread one-third of the mixture evenly on each piece of fish.
Next, sprinkle the crushed nuts on top of the mustardy salmon and pat them down gently to make sure they stick.
Place the tray in the oven for about 10 minutes or until the salmon is cooked through to your desired doneness. If you’re cooking a whole 1-pound filet, you may need to increase the baking time to 15 minutes.
Take the salmon out of the oven and let the fillets rest for a few minutes before serving.