Preheat the oven to 375°F (190°C) and line a baking sheet with parchment paper.
Rinse the salmon side and pat dry with paper towels; cut into 4 fillets (about 6 ounces each). Arrange fillets skin-side down on the prepared baking sheet and season both sides with salt and pepper.
In a small bowl, whisk together the minced garlic, Dijon mustard, honey, and lemon juice until combined.
Add the finely chopped pistachios to the mustard mixture and stir until evenly coated and slightly paste-like.
Divide the pistachio mixture among the fillets and press it firmly onto the tops to form an even crust.
Bake on the middle rack for 18–20 minutes, until the salmon flakes easily and reaches 145°F (63°C) at the thickest part.
Remove from the oven and let rest a few minutes before serving.
