Preheat oven to 425 degrees F. Line a rimmed baking sheet with parchment paper. Place cod on the baking sheet. Sprinkle the cod fillets with 1/4 teaspoon salt and pepper.

In a food processor, pulse pistachios, panko, garlic, and remaining salt, for about 10-15 seconds until a crumbly texture is reached.

In a small bowl, mix together the yogurt, mustard, and lemon zest. Using a pastry brush or mini spatula, evenly spread the yogurt mixture in top of each fillet. Evenly, gently press the pistachio mixture on top. Drizzle olive oil over the fillets. (Alternatively use and olive oil cooking spray.

Bake until fish is opaque throughout, approximately 12 to 14 minutes.