Preheat your oven to 400°F (200°C) and line a baking dish with parchment paper.

Place the salmon fillet skin-side down in the baking dish, season with salt and pepper, and spread a layer of dijon mustard on top.

In a medium bowl, combine crushed pistachios, grated parmesan, minced garlic, and melted butter until mixed.

Scoop the pistachio mixture onto the mustard-coated salmon and press it down gently.

Bake in the oven for 8-12 minutes until cooked through and golden brown. Optional: broil for extra crispiness.

Remove from oven and let rest for a minute. Garnish with parsley and a squeeze of lemon juice before serving.