When you want an easy, yet impressive weeknight dinner or date night in, butter poached cod is just as delicious as it is elegant.
Fresh cod cooks slowly in clarified butter, poaching is gently and infusing the fish with tarragon, garlic, and chili (if you like a little heat!). The cod is impossibly tender; think melt in your mouth and fall apart on a fork.
The thing that takes it over the top? Our homemade aioli recipe! We’re flavoring a simple aioli with fresh tarragon, and it is the perfect way to finish the cod.
We think you’ll agree this butter poached cod with tarragon aioli is as luxurious as it gets!
*This post was sponsored by Kings Food Market. All opinions are my own. I only support and promote brands that I believe in and use in my own kitchen – I hope you’ll check them out! Thank you for supporting the brands that make Well Seasoned possible.
Ingredients For Butter Poached Cod
For the poached fish:
- Butter, unsalted
- Fresh cod
- Fresh tarragon
- Garlic cloves, smashed
- 1 red or green chili thinly sliced, optional
- Kosher salt
- Freshly ground black pepper
For the clarified butter:
- An egg
- Garlic, minced
- Fresh lemon juice
- Canola oil
- Extra virgin olive oil
- Kosher salt
- Freshly ground black pepper
- Fresh tarragon, finely chopped
How To Make Clarified Butter
To make butter poached fish, we’ll first need to make clarified butter. Don’t worry, it’s easy!
Place butter in a large skillet or sauce pan over low heat until melted. Allow to cook until the milk solids float to the top. Once the butter stops bubbling, use a spoon to skin the foam off the top of the butter, then discard.
What remains is clarified butter! You can pass this through a sieve or fine mesh strainer if you care about removing every last milk solid, but we usually skip this step.
Poaching Fish In Butter
When you poach cod in butter, you are left with juicy, succulent fish that gently flakes apart and melts in your mouth. Truly ethereal!
Place seasoned cod filets into warmed clarified butter steeped with garlic, tarragon, and chilies (if using). Cover the pan, then cook over medium heat until just cooked through, about 6-10 minutes, based on thickness. The fish is ready when an internal temperature of 120 F is reached.
We recommend the Thermapen MK4 to check for doneness on all meats!
Thinner pieces of cod (the tail end) will finish cooking before the tenderloin (thicker piece). You can carefully remove the cod as it finishes cooking with a large spatula or spoon, then transfer to a plate or serving platter while the remaining pieces cook through.
It’s okay if the cooked cod pieces fall apart. This might happen because it’s so tender. It’s all going to the same place anyway!
Homemade Tarragon Aioli
While poached cod on its own is delicious (shoutout to the fresh tarragon, garlic, and sliced red chili helping to flavor the poaching liquid!), it is 100x better with our homemade aioli recipe spooned on top!
Don’t love tarragon? You could replace it with any other fresh herb you love; oregano or parsley are great options. But tarragon and fish go so well together. We highly recommend!
To make the tarragon aioli:
- Place the egg, minced garlic, and lemon juice into the bowl of a food processor fitted with blade attachment. With the motor running, slowly stream in the canola oil until the sauce has thickened up, about 30 seconds – 1 minute. Scrape down the sides as needed, process once more, then transfer to a bowl.
- Slowly stream in the extra virgin olive oil while whisking constantly until incorporated and thick.
- Add chopped tarragon, salt, and pepper, then mix to combine.
So completely delicious over the butter poached cod!
What To Serve With Poached Cod
We love to serve poached fish over creamy mashed potatoes. The combined texture of the two is totally luscious. Make sure to serve a crunchy vegetable on the side, either oven roasted broccoli or even a nice arugula salad would be great!
If you make this Butter Poached Cod recipe, please let us know by leaving a review and rating below!
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For more of our favorite dinner recipes, check out the following:
- Braised beef pappardelle
- Salmon piccata
- Butternut squash risotto
- Chicken Milanese with fennel
- Spicy crab pasta
Butter Poached Cod Recipe
Ingredients
For the poached fish
- 2 lbs butter unsalted
- 1 ½ lb cod
- 3 sprigs fresh tarragon
- 2 cloves garlic smashed
- 1 red or green chili thinly sliced, optional
- 1 tsp Kosher salt
- ¼ tsp freshly ground black pepper
- Chives finely chopped, for serving
- Sea salt for serving
For the tarragon aioli
- 1 large egg
- 1 clove garlic minced
- 4 tsp fresh lemon juice
- ½ cup canola oil
- ½ cup extra virgin olive oil
- ½ tsp Kosher salt
- ⅛ tsp freshly ground black pepper
- 2 Tbsp fresh tarragon finely chopped
Instructions
Make the clarified butter
- Place 2 lbs butter in a large skillet or sauce pan over low heat until melted. Allow to cook until the milk solids float to the top. Once the butter stops bubbling, use a spoon to skin the foam off the top of the butter, then discard. What remains is clarified butter!
Cook the fish.
- Add 3 sprigs tarragon, garlic, and sliced chili (if using) to clarified butter, then warm over medium heat. Make sure the skillet is large enough to fit all pieces of cod in an even layer.
- Cut cod into 3 or 4 roughly equal sized pieces.. Season cod on both sides with 1 tsp salt and ¼ tsp pepper. Add the cod to the warm butter, then cover and poach until cooked through, about 6-10 minutes. Thinner pieces of cod (the tail) will finish cooking before the tenderloin (thicker piece). You can carefully remove the cooked cod with a large spatula or spoon and transfer to a plate or serving platter while the remaining pieces cook through. Meanwhile, make the tarragon aioli.
Homemade tarragon aioli
- Place the egg, minced garlic, and 4 tsp lemon juice into the bowl of a food processor fitted with blade attachment. With the motor running, slowly stream in ½ cup canola oil until the sauce has thickened up, about 30 seconds – 1 minute. Scrape down the sides as needed, process once more, then transfer to a bowl.
- Slowly stream in ½ cup extra virgin olive oil while whisking constantly until incorporated and thick.
- Add chopped 2 Tbsp tarragon, ½ tsp salt, and ⅛ tsp pepper, then mix to combine. Serve over poached cod. Garnish with chives, a tiny sprinkle of sea salt, and some freshly cracked black pepper.
Notes
- When making clarified butter, you will lose about 25% of the volume that you begin with. It’s easy to scale up or scale down the quantity you make, as needed. Clarified butter can be used in any recipe that calls for butter, and is especially delicious served alongside seafood, such as lobster or crab, mixed in with scrambled eggs, or with any vegetable side dish.
- When stored properly in a sealed, airtight container, clarified butter will keep for up to 6 months in a refrigerator.
- To make aioli with an immersion blender: place egg, garlic, and lemon juice in a glass or cup large enough to fit the head of the immersion blender. Add canola oil, then place the immersion blender in and turn on. Process until aioli forms, lifting and tilting the head of the blender slightly so that the sauce is well incorporated. Transfer to a bowl, then continue with instructions to stream in, whisk olive oil, and then add tarragon.
Tell us about the red cabbage? shown in the photo? seared? grilled?
What is the advantage in clarifying the butter beforehand?
Thanks+
Hi Mike! That’s actually a charred radicchio salad. If you’re not familiar with radicchio, it is quite bitter. You can grab the recipe here, which is paired with balsamic (for sweetness), honey, lemon, and cheese.
When you remove the milk solids and water (from clarifying butter), you are left with only the butterfat. This has a higher smoke point, meaning that it is less likely to burn. If you do not clarify the butter first, the milk solids will cause it to burn. Hope this helps! xo, Ari
Do you throw away the leftover clarified butter after using it or is it reusable?
Cheers,
H
Hi Hugo! You can definitely save the oil to use again in a similar preparation. I’d stick to using it with other seafood dishes because of the flavor — it’ll infuse as it cooks. Store in an airtight container in the fridge and use within a month. It’ll congeal, but can be melted or allowed to come to room temperature to soften, as needed. Hope this helps! xp, Ari