Pat the cod fillets dry with paper towels to ensure a good sear, then season both sides generously with salt and pepper.
Heat a non-stick skillet over medium-high heat until shimmering, about 2 minutes, then add olive oil and swirl to coat the pan evenly.
Place the cod fillets in the hot pan skin-side down if they have skin, pressing gently to ensure contact and prevent curling. Cook for 3-4 minutes until the edges look opaque and golden brown.
Carefully flip each fillet with a spatula and cook for another 2-3 minutes until the fish flakes easily and is just cooked through.
Remove the fish from the pan and set aside on a warm plate, covering loosely with foil if needed to keep warm.
Reduce the heat to medium, then add the butter to the same pan, allowing it to melt and foam gently, filling the kitchen with a rich aroma.
Add the minced garlic to the butter, cooking for about 30 seconds until fragrant and slightly golden, stirring constantly.
Stir in the lemon zest and then squeeze in the lemon juice, whisking continuously to combine into a bright, glossy sauce. Let it simmer gently for about a minute to thicken slightly.
Taste the sauce and adjust with salt and pepper as needed, then remove from heat to prevent separation.
Plate the flaky cod fillets and spoon the lemon butter sauce generously over each piece, then garnish with chopped parsley or dill for a fresh pop of color and flavor.
Serve immediately, enjoying the tender fish coated in a vibrant, buttery lemon sauce that’s perfect for a cozy, elegant dinner.
