Potato-Crusted Chilean Sea Bass with Herb Butter Sauce

This Chilean sea bass recipe is based on a classic French preparation by Paul Bocuse, where he used thin potato slices to mimic fish scales on a fillet. His version is a little more complex. I've simplified the process, and now this is one of the most impressive dinners I can put on the table with 30 minutes of active cooking.

The technique is mostly patience. You shingle thin potato slices over the fillet, chill it for 30 minutes, then sear the whole thing potato-side down until you get a golden, crackling crust that holds together when you flip it. The herb butter sauce takes about two minutes in the same pan.

If you can use a mandolin, you can make this.

If you love Chilean Sea Bass as much as I do, you'll have to try my Baked Chilean Sea Bass with Garlic Herb Butter or Air Fryer Miso Sea Bass next! And if pan sauce over fish makes you happy, try my Lemon Piccata Sauce.

Ingredients:

Before we get to the step by step directions, a few notes about the ingredients:

Fish: Chilean sea bass is ideal here -- its thickness holds up to the sear and its richness pairs perfectly with the buttery sauce. I used Sizzlefish's sea bass fillets the last time I made this recipe. They come skinless, which works well here. I've also made it with skin-on fillets for this preparation and the crispy skin was lovely. Either one works!

You can also use halibut or black cod. I've tested this with Atlantic cod and European sea bass (branzino) as well - both work, though neither has the richness of Chilean sea bass.

Potatoes: Yukon gold or fingerlings. Look for small ones that are roughly the same size so your slices are consistent.

Herbs: Flat leaf parsley in the butter sauce. Fresh chives or basil also work.

Full ingredient list and measurements included in the printable recipe card below.

Why This Recipe Works:

The 30-minute chill after you build the crust is essential. The clarified butter you brush on the fillet and over the potatoes acts as the adhesive, and chilling it firms everything up so the potato slices stay put when you transfer the fillet to the pan. Skip this step and you'll be chasing potato slices around a hot skillet.

Clarified butter (or ghee) is equally important for the sear. You're cooking at medium-high heat to brown the potatoes before the fish overcooks, and regular butter's milk solids will burn at that temperature. Ghee handles the heat cleanly and adds a rich, nutty flavor to the crust.

The butter sauce gets made in a wiped pan over medium heat, which is why it stays silky and bright instead of greasy. Two minutes, fresh lemon, fresh parsley - it's the right amount of sauce for a crust this good.

Step by step instructions:

1. Prep potatoes

Using a mandolin on its thinnest setting, slice 2-3 small Yukon gold potatoes. Rinse in cold water and set aside to dry.

2. Season and prep sea bass

Pat fillets dry with paper towels. Season one side generously with salt and pepper - this is the bottom side. (If using skin-on fillets, season the skin side first, then flip and apply the butter and potato scales to the flesh side.)

Flip, then brush the other side (the presentation side) with a half tablespoon of clarified butter and lay potato slices across the entire surface, shingle-style.

Brush a little more clarified butter over the potatoes to keep them glued together, then season the top of the potatoes with salt. Cover each fillet gently with a small piece of parchment and refrigerate for 30 minutes.

3. Sear sea bass

Heat a skillet over medium-high heat. Add the remaining 2 tablespoons of clarified butter. Leaving the parchment in place to act as insurance against sticking, place fillets potato-side down and leave undisturbed for 3-4 minutes. Use a fish spatula to check the crust - you want a deep golden brown before you flip.

Flip gently and cook another 3-4 minutes, basting as needed for a golden brown potato topping. Cook until the fish reaches an internal temperature of 135°F. It will carry over to 140°F while it rests.

4. Make butter sauce

Remove fillets from the skillet. Wipe out the pan and return to medium heat. Add 2 tablespoons of butter and melt. Add lemon juice and parsley, cooking for just a minute and swirling the pan to heat everything through. Taste and adjust salt and pepper.

5. Garnish and serve

Pour butter sauce onto the plate before adding fish and veggies (I love serving with steamed spinach).

What other fish can I use in this recipe?

This Chilean sea bass recipe can be replicated using several other white fish varieties, especially halibut or black cod (sablefish). But I've also tested this recipe using regular Atlantic cod and European sea bass, and both turned out beautifully. They don't have the luxurious texture and richness that Chilean sea bass offers, but the light, flaky fish created a great platform for the crispy, buttery potato scales.

Can I use regular butter instead of clarified butter or ghee?

The relatively high heat we use to brown the potato scales and the skin may burn the milk solids in regular butter. Ghee is pure butter with the milk solids removed, so it has a very clean flavor and does not contain the dairy that can burn. I love the flavor of it in this dish and the worry-free nature of using it for browning both the potatoes and the fish. For the butter sauce, regular butter is ideal as the dairy adds a luscious creamy quality to the sauce.

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