This spiced tomato butter salmon is one of my favorite easy, quick and delicious ways to make salmon. The salmon skin gets all crispy, and the sauce is built around the salmon as it’s cooking, so it ends up gripping to the fish and caramelizing onto the skin as everything cooks. It’s deeply flavorful and incredibly satisfying, plus – the whole process takes less than 15 minutes, and 10 if you are prepped and ready to go.
I like this salmon recipe in the summertime (salmon is seasonal by the way, it’s caught in the summer!) because it’s perfect for when you don’t want to turn on your oven. However, it’s also pretty amazing year-round, since this subtly spiced tomato butter is filling, rich and the perfect level of sweet-to-smokey.
I’ll leave the full recipe below, along with some advice about how to use a cast iron vs. stainless steel pan for this recipe (you could use either) AND how to protect your cast iron if that’s the route you choose to go. Either way, this salmon will deliver a delicious dinner.
What is tomato butter?
In this recipe, tomato butter refers to the sauce – and it is gooooood. This is a sauce that’s almost reminiscent of a barbecue style sauce, using tomato paste, brown sugar and mustard seed as part of the building blocks of the sauce.
Here “tomato butter” means that the base of the sauce is a brown butter, which starts in the pan with the salmon as it finishes cooking. It’s then quickly combined with tomato paste, brown sugar, vinegar, cumin, mustard seeds and red pepper flakes to make an easy, thick and highly spoonable salmon sauce. It’s not a proper compound butter, but on salmon, tomato butter is the absolute best.
What type of pan should I use for this salmon?
I developed this recipe on a cast iron pan, however, I understand there are always concerns about cooking acidic ingredients on a cast iron pan, and this recipe is highly acidic. While I don’t claim to be a food scientist or expert, here are my recommendations for which pan to use for this recipe, based on my personal experience.
I like to use cast iron because it retains a high and even level of heat across its surface. However, it’s only best to use if it is very well seasoned and has been in use for some time. If you do use a cast iron, the pros are that you will get a darker crust on your salmon, with a slightly crispier skin.
However, cast irons tend to have a higher tendency to smoke, since their seasoning is made of carbonized oil. If you don’t have a well ventilated kitchen, you might prefer a stainless steel pan.
What’s nice about stainless steel is it will get you very similar results to cast iron. The sauce might not darken as much, and it might take a few more minutes for the butter to brown, but your salmon skin will still get crispy and it will skill cook in a similar amount of time. If you are nervous about the seasoning on your cast iron, or if you just want an easier clean-up process, stainless steel is a great route to go.
How to use acidic ingredients in your cast iron pan
Now let’s do some MYTH BUSTING – brought to you by research that America’s Test Kitchen did, as well as myself over here at Snacks HQ.
There is general advice not to cook acidic things on cast iron pans – think: tomato sauce, wine, vinegar-based sauces, etc. This is because as those ingredients cook for an extended period of time, trace amounts of molecules from the metal can leach into the food. The key word here is extended period of time. America’s Test Kitchen had testers simmer tomato sauce for a long period of time to taste for flavor differences, and you can read more about their results in the link above.
My key takeaways from their research has long been a guiding light in my cooking and recipe development. Whenever I cook acidic foods in a cast iron, I follow the following guidelines to protect both my food and my pan:
- Always ensure my pan is well-seasoned – a well-seasoned pan can hold up to a myriad of acidic ingredients for a reasonable period of time.
- Make sure my pan has a liberal layer of fat before adding anything acidic – this acts as a barrier as an acidic sauce is built, which is why this tomato butter begins with a butter base first.
- Add acidic ingredients at the end, and only for a short amount of time – the tomato butter cooks in this recipe for a maximum of five minutes.
- Remove the sauce from the pan as soon as it is ready for serving – there’s no need to let an acidic sauce sit in a cast-iron, and this is just a safety net to protect your pan!
- Wash and properly dry after the sauce is made – you can also reseason if you like, but I never feel the need.
So all that to say – don’t be afraid of making this tomato butter in your cast iron. Just take a few proper precautions to protect it, and you should be all set!
And that’s it for this tomato butter salmon!
And of course feel free to leave any questions, comments or reviews! This is the best place to reach me, and I’d love to hear from you.
Tomato Butter Salmon
- 1 large cast iron or stainless steel pan
- 1 pair of tongs
- 1 & 1/2 pound salmon fillet portioned into 4 pieces
- Diamond Crystal kosher salt
- Freshly ground black pepper
- 1 tablespoon extra-virgin olive oil
- 2 tablespoons salted butter
- 1 tablespoon light brown sugar packed
- 1 heaping tablespoon tomato paste
- 1 tablespoon & 2 teaspoons white wine vinegar
- 1/2 teaspoon mustard seeds
- 1/2 teaspoon ground cumin
- 1/4 teaspoon red pepper flakes
- Season each salmon fillet with a pinch of salt and a few cracks of black pepper on either side.
- Place either a cast iron or stainless steel pan over medium heat. If using a cast iron, see blog post for notes.
- Add the olive oil to the pan and swirl to coat. When the pan is properly heated, add the salmon, skin side down. Let this cook for 6-7 minutes, undisturbed, until the edges of the skin are beginning to turn slightly gold. Gently flip the salmon fillets.
- Add the butter to the pan and let it fully melt and begin to brown, gently push the salmon fillets to one side of the pan.
- In a small bowl, whisk together the sugar, tomato paste and vinegar so everything is smooth, then pour into the pan with the butter. Stir vigorously, toasting the tomato paste and encouraging everything to combine with the butter. Tilt the pan so that the butter runs into the tomato paste mixture, and you will see everything begin to form a smooth sauce. This will all happen in about 1-2 minutes, it goes quick!
- Add the mustard seeds, cumin, and red pepper flakes and taste. Season with salt as needed. I also occasionally add more vinegar here if it feels like it needs it.
- Turn off the heat and gently push the salmon to the center of the pan again, swirling the sauce around the fillets. Flip the fillets onto a serving plate so that the skin side is facing down, this keeps the skin away from the sauce to keep it crispy. Spoon all remaining sauce over the tops of the fillets.