Black Bass With Preserved Lemon–Pistachio Sauce

Name: Black Bass With Preserved Lemon–Pistachio Sauce
Ingredients: 4 4–6-oz. skin-on black bass or red snapper fillets, patted dry; Kosher salt, freshly ground pepper; 1 Tbsp. vegetable oil; 4 Tbsp. unsalted butter, cut into pieces; 2 Tbsp. coarsely chopped raw pistachios; 4 garlic cloves, finely chopped; 3 Tbsp. finely chopped preserved lemon peel; 2 Tbsp. fresh lemon juice; Kosher salt; Parsley leaves (for serving)