Pat the cod fillets dry with paper towels and season generously with salt and pepper on both sides.
Heat a non-stick skillet over medium-high heat until hot and shimmering, then add olive oil.
Carefully place the cod fillets skin-side down into the hot oil, pressing gently to ensure contact. Cook for about 4-5 minutes until the skin is crispy and golden, and the fish is opaque about halfway up.
Gently flip the fillets using a fish spatula and cook for another 2-3 minutes until fully opaque and flaky. Remove the fish from the skillet and set aside.
In the same skillet, add minced garlic and cook for about 30 seconds until fragrant, taking care not to burn it.
Pour in the white wine (if using) and scrape up any browned bits from the bottom of the pan. Let it simmer for 1-2 minutes to reduce slightly.
Add the butter pieces and lemon juice, stirring constantly until the butter melts into a silky, smooth sauce. Stir in lemon zest and taste for seasoning.
Return the cooked fish to the skillet, spooning the sauce over the fillets and cooking for an additional minute to rewarm and coat evenly.
Transfer the fillets to serving plates, spoon extra lemon butter sauce over each, and sprinkle with chopped parsley.
Serve immediately with your favorite sides for a bright, flavorful meal.
