Preheat the oven to 400°F. Line a baking dish with parchment paper and place the salmon skin side down. Season with salt and pepper and spread dijon mustard on top.
In a small bowl, combine pistachios, parmesan cheese, garlic and melted butter.
Spoon the mixture over the salmon and gently press the topping on the salmon.
Bake for 8-12 minutes depending on the thickness of your salmon. Broil if desired to brown the top.
Garnish with parsley and serve with a squeeze of lemon.
Notes
Cooking times will vary depending on the thickness of your salmon.
I personally like my salmon medium rare - medium around 125-135°F.