This Whole30- and keto-friendly Poached Cod in Tomato Sauce is so simple and delicious! Even my picky kid eagerly scarfs down this deliciously easy dish (“it tastes like pizza fish!”), which is a minor miracle.
Looking to get more fish in your family’s belly but freaked out about how to cook it properly? Well, I’ve got a fool-proof and tasty recipe for you!
As a matter of fact, it’s so simple that I’m a little sheepish about posting a step-by-step recipe. I used store-bought sauce, and my only flourish was to add a sprinkle of fresh herbs at the end, so this is barely a recipe at all. In fact, when I texted my pal Diana Rodgers about posting this recipe on my blog, her reply was this: “LOL. Put fish in Rao’s sauce and turn stove on? I’m on to you. #faker.”
Guilty as charged. I’ve always been about finding and sharing shortcuts to deliciousness, so call me a faker if you want, but I like to think of myself as a lazy genius. (I’m modest, too.)
Quick 15-minute fish dinner!
This dish is on constant rotation in our house because it utilizes a few ingredients I already have stocked in my kitchen: defrosted fish fillets from my freezer and store-bought Paleo-friendly sauces in my fridge or pantry. Plus, I only dirty one pot, and the fish is ready in just 15 minutes or sooner if your fillets are thin!
My favorite online source for sustainable seafood!
Wondering where to source the best wild and sustainable seafood online? If I can’t head to my local fish monger, I love getting frozen seafood deliveries from Vital Choice. It’s not cheap, but you get what you pay for.
My favorite Whole30-friendly marinara sauces
Of course, this simple dish will only taste as good as your sauce, so pick a delicious one with high-quality ingredients. You can use homemade marinara sauce, but I don’t normally have that on hand. Instead, my pantry is stocked with jars of Whole30-friendly sauces that are both tasty and made with healthy ingredients that I would use myself if I made my own.
My favorite store-bought brands are Rao’s Homemade marinara sauce, Bianco Di Napoli organic marinara sauce, and the Kirkland organic marinara sauce available at Costco.
If you want the fish to have a Mexican flair, you can substitute salsa for the marinara sauce! The store-bought, shelf-stable Whole30-compliant salsa I like is the mild Frontera Roasted Tomato Salsa.
Can you use another fish or protein in this dish?
Yes! If you don’t have cod fillets, you can use another mild white fish fillet like halibut, pollock, bass, grouper, haddock, and even tilapia. This recipe also works great with boneless and skinless chicken breasts or thighs—just make sure the chicken is cooked through before serving.
Time to make Poached Cod in Tomato Sauce!
Serves 4
Ingredients
- 4 (6-ounce) skinless and boneless cod fillets (I buy frozen cod fillets with the Marine Stewardship Council label)
- Diamond Crystal brand kosher salt
- 2 cups Paleo-friendly marinara sauce or salsa
- Freshly ground black pepper
- ¼ cup chopped fresh herbs (e.g. chives, Italian parsley, basil, or cilantro)
Equipment
- Here’s my favorite meat thermometer. All of my other recommended kitchen tools are listed here.
Method
If you’re using frozen fillets, thaw the fish overnight in the refrigerator. Don’t be frustrated if the fillets aren’t completely thawed by dinnertime; simply place the cod packets in a bowl and run cool water on them. Let the fillets sit in the water for 10-15 minutes, and they should be ready to go.
(Obviously, you can skip the step above if you’re using fresh cod.)
Blot the fish with paper towels…
…and sprinkle both sides with salt.
Grab a skillet with a lid, and pour in about two cups of marinara sauce or salsa. The skillet should be large enough to fit the fillets snugly in a single layer. If you’re poaching four fillets, a 10-inch skillet works great.
Crank the heat up to high to bring the sauce to a boil.
When the sauce is bubbling…
…carefully slip in the seasoned fillets.
Lower the heat to about medium-low—enough to maintain a simmer.
Then, cover the pan and cook for 5 to 8 minutes or until the fish is opaque and cooked to your preferred doneness. Once the thickest part of the fish reaches 130°-140°F on an instant-read thermometer, I take the pan off the heat. (I know the FDA says 145°F is the safe temperature for cooked fish, but for my tastes, that’s overdone. Instead, I refer to this chart for fish cooking times.)
Top the fish with freshly cracked black pepper and a shower of fresh herbs.
I like to garnish the cod with Italian parsley, basil, and chives when I poach in marinara sauce, and cilantro and green onions when I poach in salsa. I’m flexible like that.
Serve the saucy fish with a giant green salad, a big platter of roasted green beans, Instant Pot steamed spaghetti squash, or cauliflower rice. How easy was that?
[Originally posted on November 29, 2016. Updated with new details and photos on May 11, 2020.]
Looking for more recipe ideas? Head on over to my Recipe Index. You’ll also find exclusive recipes on my iPhone and iPad app, and in my cookbooks, Nom Nom Paleo: Food for Humans (Andrews McMeel Publishing 2013), Ready or Not! (Andrews McMeel Publishing 2017), and Nom Nom Paleo: Let’s Go! (Andrews McMeel Publishing 2022).
PRINTER-FRIENDLY RECIPE CARD
Poached Cod in Tomato Sauce
Ingredients
- 4 6-ounce skinless and boneless cod fillets
- Diamond Crystal kosher salt
- 2 cups marinara sauce or salsa
- Freshly ground black pepper
- ¼ cup chopped fresh herbs e.g. chives, Italian parsley, basil, or cilantro
Instructions
- If you’re using frozen fillets, thaw the fish overnight in the refrigerator. Don’t be frustrated if the fillets aren’t completely thawed by dinnertime; simply place the cod packets in a bowl and run cool water on them. Let the fillets sit in the water for 10-15 minutes, and they should be ready to go. (Obviously, you can skip this step if you’re using fresh cod.)
- Blot the fish with paper towels and sprinkle both sides with salt.
- Grab a skillet with a lid, and pour in about two cups of marinara sauce or salsa. The skillet should be large enough to fit the fillets snugly in a single layer. If you’re poaching four fillets, a 10-inch skillet works great.
- Crank the heat up to high to bring the sauce to a boil. When the sauce is bubbling, carefully slip in the seasoned fillets.
- Lower the heat to about medium-low—enough to maintain a simmer.
- Then, cover the pan and cook for 5 to 8 minutes or until the fish is opaque and cooked to your preferred doneness. Once the thickest part of the fish reaches 130°-140°F on an instant-read thermometer, I take the pan off the heat. (I know the FDA says 145°F is the safe temperature for cooked fish, but for my tastes, that’s overdone. Instead, I refer to this chart for fish cooking times.)
- Top the fish with freshly cracked black pepper and a shower of fresh herbs. (I like to garnish the cod with Italian parsley, basil, and chives when I poach in marinara sauce, and cilantro and green onions when I poach in salsa.)
- Serve the saucy fish with a giant green salad, a big platter of roasted vegetables, or cauliflower rice.
Jim Brennan says
I’ve yet to make this recipe, but how can it NOT be 5 star – marinara sauce, fish, and easy?! One thing I’ve done with other recipes, that I think will work here, is a half marinara/half salsa sauce. I think I’ll try that the second time I make it. Thanks!
chris says
I’ve made this with Rao’s and it was great. Doing again tonight with fresh cod from Costco and using a jar of Indian Butter Chicken Sauce, also from Costco (and also low carb). Ingredients not too different from marinara sauce, just different spices. (in order: Tomato puree, diced tomatoes, heavy cream, ginger, onion, garlic, canola oil (not paleo, but 7th ingredient), cane sugar (again not paleo), butter, salt, spices).
Dana says
So easy and so good! Used Raos. Thank you for the recipe this is probably my 4th time making it.
Kirstin C says
So delicious and one of our favorites!
Leslie says
Love this. It’s surprisingly good with salmon filets as well, as I discovered once when I thought I had cod but didn’t. I like to include some capers and or olives.
Rebecca says
Nice reminder that a healthy dinner can be quick and easy. I used cod pieces and the basil marinara (both) from Trader Joe’s and then threw in some think-cut zucchini in the sauce to simmer. I’ve done your salsa version with chicken but never with fish. Will have to try that one next. Thank you for these!