Let fish drain in a colander at room temperature while you prepare the sauce.
In a large pan over medium heat, add butter, onion, and garlic and stir often until butter is melted and onions are translucent, about 2 minutes. Take care that butter doesn’t burn.
Add broth and lemon juice. Boil for 2-3 minutes until sauce thickens slightly. Stir in lemon zest, parsley, ½ teaspoon kosher salt, and ¼ teaspoon black pepper. Remove from heat and cover to keep warm.
Use clean paper towels to pat dry fish fillets to remove as much excess moisture as possible. Sprinkle a very light, even layer of kosher salt and black pepper over both sides of fish. If desired, sprinkle evenly with a light layer of smoked paprika.
Heat olive oil to a large nonstick frying pan over medium-heat. Once oil is hot arrange 2 fillets in pan, with a lid ajar to allow steam to escape. Do not move fish around. Let cook 3-4 minutes or just until bottom of fillets are browned.
Use a large, flat spatula to carefully flip fish and cook another 3-4 minutes on the other side. Repeat with remaining 2 fillets.
Plate rockfish onto serving plates and our warm lemon butter sauce over them. Serve immediately.
Notes
Use a nonstick skillet to get a clean sear without the risk of sticking. Avoid cast iron, which tends to cling to delicate fish fillets even when oiled.
Dry the fish thoroughly with clean paper towels before seasoning. Removing excess moisture ensures a crisp, golden crust instead of a soggy texture.
Don’t overcrowd the pan. Cook the fish in batches if needed, giving each fillet enough space to brown evenly without steaming.
Make the lemon butter sauce ahead of time to save time on busy nights. You can store it in the fridge for up to 2 days and reheat gently on the stovetop or in the microwave before serving.
Let the fish cook undisturbed for 3–4 minutes per side to develop a flavorful crust. Use a wide, flat spatula to flip carefully and keep the fillets intact.
Serve immediately for best texture and flavor. While leftovers can be stored in the fridge for up to 3 days, pan seared fish tastes best fresh from the skillet.
If you enjoyed this recipe, please come back and give it a rating. We ❤️ hearing from you! Join our Free Recipe Club and get our newest, best recipes each week!