This Chilean bass recipe pairs thick, mild fillets with a crisp golden sear and a quick lemon-garlic butter sauce. Chilean sea bass is the market name for Patagonian toothfish, a fish from cold waters around southern South America and the Antarctic; this simple preparation is inspired by coastal cooking, not a claim that there is one traditional national recipe.
Ingredients
- 4 skinless Chilean sea bass fillets, about 6 ounces (170 g) each, roughly 1 inch (2.5 cm) thick
- 1 teaspoon fine salt (6 g), or to taste
- ¼ teaspoon freshly ground black pepper (about 0.5 g)
- 1 tablespoon neutral oil, such as avocado or canola oil (15 ml)
- 3 tablespoons unsalted butter (42 g), divided
- 2 garlic cloves, finely minced (about 6 g)
- 1 teaspoon finely grated lemon zest (about 2 g)
- 1 tablespoon fresh lemon juice (15 ml), plus 1 lemon cut into wedges for serving
- 1 teaspoon fresh thyme leaves (about 1 g), or ¼ teaspoon dried thyme (about 0.3 g)
- 1 tablespoon chopped fresh parsley (about 4 g)
Instructions
- Heat the oven and prepare the fish. Set a rack in the center of the oven and heat it to 400°F (200°C). Allow about 15 minutes for the oven to heat while you prepare the ingredients. Pat the fillets very dry on all sides with paper towels; this is important for browning, since moisture on the surface makes the fish steam. Check for pin bones by running a clean fingertip along the center of each fillet and pull out any bones with clean tweezers. Season both sides with the salt and pepper.
- Heat the pan. Choose a heavy, oven-safe skillet large enough to hold the four fillets without crowding; use two pans or cook in batches if needed. Heat the oil over medium-high heat until it shimmers, about 1 to 2 minutes. If the oil smokes heavily, lower the heat and let the pan cool briefly before adding the fish.
- Sear the first side. Lay the fillets in the skillet with a little space between them. Place them away from you to avoid splashing hot oil. Leave them undisturbed for 3 minutes so a golden crust can form. If a fillet sticks, give it another 20 to 30 seconds rather than forcing it; it will usually release more easily once the surface has browned.
- Turn and move the skillet to the oven. Carefully turn each fillet with a thin spatula and sear the second side for 2 minutes. Transfer the oven-safe skillet to the preheated oven and roast for about 7 minutes. Thickness and starting temperature affect the finish time, so begin checking the thickest part after 5 minutes. The USDA FSIS safe minimum internal temperature for fish is 145°F (63°C); check each fillet in its thickest part with an instant-read food thermometer, avoiding contact with the pan.
- Make the lemon butter. Move the cooked fillets to a warm plate and loosely cover them while you make the sauce. Carefully return the skillet to the stove over low heat; its handle will be hot, so use an oven mitt. Add 2 tablespoons of the butter and the minced garlic. Stir for about 30 seconds, just until fragrant, without letting the garlic brown. Add the lemon zest, lemon juice, thyme, and remaining 1 tablespoon of butter. Swirl the pan for about 1 minute until the butter melts and the sauce looks glossy. Stir in the parsley, taste, and add a pinch of salt or pepper if needed.
- Sauce and serve. Spoon the warm lemon butter over the fillets and serve promptly with lemon wedges. If the fish is ready before the sauce, keep it loosely covered for only a few minutes; long holding can dry out the delicate flesh. The sauce should taste bright and buttery, not sharply sour. Add a little extra butter if the lemon is especially tart.
Tips
- Dry the surface well. Moisture is the main obstacle to a crisp sear. If the fish has been thawed, pat it dry especially thoroughly, and do not rinse it under running water. Keep the fillets in the refrigerator until you are ready to season them.
- Use a thermometer instead of relying on the clock. Fillets can vary in thickness, and a thin tail piece cooks more quickly than a thick center cut. Start checking early and remove each piece once it reaches 145°F (63°C). Overcooking makes this naturally rich fish firm and dry.
- Choose a suitable substitute if needed. Black cod, also called sablefish, is a rich substitute and cooks in a similar way, though it can be softer. Halibut or cod works too, but is leaner and may need a minute or two less in the oven. Keep the same temperature target and check the thickest part.
- Do not crowd the skillet. When fillets touch, they release moisture into the pan and brown less effectively. Cook in batches if your skillet is small, and transfer the first batch to a warm plate while the next cooks. Wipe out burnt oil before making the butter sauce.
Serving Suggestions
Serve each fillet with a spoonful of sauce and a lemon wedge. The buttery fish goes well with plain rice, herbed potatoes, or crusty bread, all of which can take up the sauce without competing with it. For a lighter plate, pair it with steamed green beans, asparagus, sautéed spinach, or a crisp salad dressed with a simple vinaigrette. Add a vegetable with a little freshness or acidity to balance the richness of the fish.
If you are serving a group, bring the skillet sauce to the table in a small warmed bowl rather than pouring it all over the fish in advance. That keeps the seared surface from softening and lets diners choose how much sauce they want. A modest sprinkle of parsley and a little freshly grated lemon zest make a clean finish; extra salt is often unnecessary after the fish has been seasoned.
Variations
Make it with a white-wine pan sauce: After moving the cooked fish to a plate, add 2 tablespoons (30 ml) of dry white wine to the skillet and simmer for about 1 minute, scraping up browned bits. Add the butter and garlic, then continue with the lemon and herbs. The wine makes the sauce lighter and a little more aromatic; it is optional, and the basic version needs no alcohol.
Add capers: Stir 1 tablespoon (8 g) of drained capers into the finished lemon butter. Their salty, briny flavor is a good match for rich fish, so taste the sauce before adding any extra salt.
Use a different herb: Replace thyme with 1 teaspoon (about 1 g) of chopped dill or chives, added at the end. Dill gives the dish a fresher, more delicate character, while chives add a mild onion note. If fresh herbs are unavailable, use the smaller dried-thyme quantity listed above rather than substituting dried dill or chives in equal amounts.
Choose a lighter finish: Replace half the butter with 1 tablespoon (15 ml) of olive oil and use a little more lemon juice to taste. The sauce will be less creamy and more citrus-forward. Do not reduce the cooking oil in the pan too far; a thin coating helps the fish brown evenly.
Storage and Reheating
Refrigerate cooked fish within 2 hours of cooking, storing it in a shallow airtight container. Keep the fillets and any extra sauce together or in separate containers; either way, use the leftovers within 3 to 4 days. If the room is hotter than 90°F (32°C), refrigerate the fish within 1 hour. Do not leave it at room temperature for a long meal or pack it away while it is still sitting out.
For best texture, reheat only the portion you plan to eat. Place the fish in a covered oven-safe dish with a teaspoon of water or a little extra butter, then warm it in a 275°F (135°C) oven until it reaches 165°F (74°C), the USDA FSIS temperature for reheated leftovers. Check with a food thermometer. The time depends on the thickness and whether the fish is cold from the refrigerator, so check after about 10 minutes rather than relying on a fixed duration. A microwave can also work: use a covered microwave-safe dish and short intervals at medium power, checking the center so the edges do not become rubbery. Reheated fish will not have quite the same crisp surface as freshly cooked fish. Freeze leftovers in a well-sealed container for up to 2 months for best quality, then thaw them in the refrigerator before reheating.
Frequently Asked Questions
Is Chilean sea bass actually bass?
It is not a true bass. Chilean sea bass is the common market name for Patagonian toothfish, a deep-water fish found in cold southern oceans. The name is widely used in seafood markets, but the species name is more precise. It is known for firm, moist flesh and a rich texture, which is why it works well with a simple pan sear and a bright sauce.
Can I use frozen Chilean sea bass?
Yes. Thaw it in the refrigerator, ideally overnight, and keep it cold until cooking. Remove it from its package if the package instructions call for that during thawing, and place it in a covered dish to catch drips. Pat the thawed fillets very dry before seasoning. Avoid thawing fish on the counter or in warm water, because those methods leave it at room temperature for too long and can make the surface waterlogged.
Can I cook the fillets with the skin on?
Yes, provided the skin has been scaled and is suitable for eating. Dry the skin thoroughly, start the fillet skin-side down, and press it gently with a spatula for the first 20 to 30 seconds to help it stay flat. Sear the skin side for about 3 minutes, then turn the fish and proceed with the oven step. Skin thickness varies, so use the same thermometer check rather than assuming the original timing will be exact.
How can I tell when the fish is done without cutting it open?
A food thermometer is the most dependable way: insert it sideways into the thickest part of the fillet and look for 145°F (63°C). The flesh should also look opaque and separate into large flakes when gently pressed, but those visual cues are less precise than temperature. If a thin piece reaches the safe temperature before a thicker one, take it out and let the thicker fillet continue cooking.
Why did my fish stick to the pan or break when I turned it?
The pan may not have been hot enough, the fillet may have been wet, or it may have been turned too soon. Dry the fish, let the oil shimmer before adding it, and leave the first side alone for the full searing period. Use a thin, wide spatula to support the fillet as you turn it. Even if a piece breaks, it will still taste good; spoon the sauce over it and serve it as planned.
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Safety notes: safe minimum internal temperatures from USDA FSIS; raw and undercooked fish guidance from the U.S. FDA. Food safety notes
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