Fiesta Baked Cod
Published May 8, 2022 • Updated March 12, 2026
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This easy baked cod comes together in about 10 minutes with just 4 ingredients. I top cod filets with balsamic vinaigrette, Rotel, and cheddar cheese for a simple keto dinner that my family genuinely looks forward to.
Sometimes I have about 10 minutes before my family starts asking what’s for dinner. That’s when I pull this recipe out. Four ingredients, one baking dish, and the cod comes out flaky and full of flavor every single time. It’s the same kind of low-effort cooking I love about my sheet pan chicken and veggies and salsa chicken, where cleanup barely registers as a chore.
I almost always use frozen cod. It’s the protein I grab when I forgot to plan dinner, because it thaws in about 20 minutes in a cold water bath. Most cod comes in individual vacuum-sealed portions too, so I skip the weighing and cutting entirely. Zero carbs, high protein, and it pairs with just about anything in my pantry.
The real trick here is the balsamic vinaigrette. I keep a bottle in the fridge at all times, and one can of Rotel in the pantry. The vinaigrette gives the fish a tangy, slightly sweet glaze while the tomatoes and green chilies bring enough kick that nobody reaches for hot sauce. I finish with a handful of sharp cheddar right before it goes in the oven, which melts into this golden layer on top. Most cod recipes default to lemon and garlic butter. I’ve made it that way too, but the balsamic-Rotel combo has more going on and it takes zero extra effort.
I serve this with roasted broccoli most nights, or cauliflower rice when I want something to soak up the juices from the Rotel. Sheet pan fajitas sides (peppers and onions with a squeeze of lime) pair well too if you want more color on the plate. One reader told me her daughter, who usually pushes fish to the edge of her plate, finished her piece and asked for more. That’s the reaction I want from a keto dinner, not just something that checks a nutrition box.
If you want more fast weeknight options, my garlic butter shrimp is the closest thing in my seafood rotation. My keto beef and broccoli follows the same no-fuss approach for the nights nobody wants fish. And if you’re stuck in a low carb dinner rut, crustless pizza always breaks the pattern.
How to bake cod in 3 steps
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Ingredients
1 pound cod filets -
2 tablespoons avocado oil, olive oil or melted butter
-
1/4 cup balsamic vinaigrette
-
4 oz Rotel, drained
-
1/2 cup shredded sharp cheddar cheese
Step by Step Instructions
Step by Step Instructions
Layer cod & season
Preheat oven 425 degrees. Pat cod filets dry with a paper towel and add to the bottom of a square baking dish. Season with salt.
Add flavor
Evenly pour balsamic vinaigrette over the cod. Top with Rotel. Sprinkle shredded cheese all over.
Nutrition disclaimer
The nutrition information provided is an estimate and is for informational purposes only. I am a Doctor of Pharmacy (Pharm.D.); however, this content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician or other qualified health provider before making any lifestyle changes or beginning a new nutrition program.
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Get My Macros + Recipes →Frequently Asked Questions
What temperature should I bake cod at?
I bake my cod at 425 degrees for 10 minutes. The key is making sure all the filets are roughly the same thickness so they cook evenly. If I have one piece that's noticeably thicker, I give it an extra 2-3 minutes.
How do I know when cod is fully cooked?
I check by pressing a fork into the thickest part and giving it a gentle twist. If the fish flakes apart easily and the flesh is bright white all the way through, it's done. The internal temperature should hit 145 degrees F. I've overcooked cod exactly once (went to 15 minutes) and it turned rubbery, so I set a timer now.
Can I freeze baked cod?
I've frozen leftover cod a couple of times and it's fine, but the texture does get a bit softer after thawing. I wrap each piece individually in plastic wrap, then put them in a freezer bag. They keep for about 2 months. I reheat from frozen in my air fryer at 350 for about 6 minutes.
What can I substitute for balsamic vinaigrette?
I prefer balsamic vinaigrette because it adds both acid and a touch of sweetness. If I'm out of it, I use plain balsamic vinegar but drizzle much less (maybe a tablespoon total) since it's more concentrated. Lemon juice also works. I've used it when I wanted a lighter, brighter flavor on the fish.
Should I bake cod covered or uncovered?
I always bake this uncovered. The cheese on top needs direct heat to melt and get that golden layer. If I covered it, the cheese would just steam and never crisp up. I've tried it both ways and uncovered gives a much better result.
How much cod fits in an 8x8 baking dish?
I typically fit about 1 pound of cod in my 8x8 inch dish. I cut the filets into smaller pieces to make them fit in a single layer. If I'm cooking for more than two people, I use a 9x13 dish and scale the vinaigrette and Rotel up by half.
What should I serve with this?
I keep it simple. Roasted broccoli or asparagus on another sheet pan while the cod bakes, or cauliflower rice when I want something to catch the Rotel juices. On lazy nights, I just do a bag of steamable green beans. I've tried more elaborate pairings, but this dinner is built to be fast, and a fussy side defeats the purpose.
Can I use a different cheese?
I've tested pepper jack in place of the sharp cheddar and it adds real heat without changing the cook time. One of my readers made the swap and said it was the best version. Mozzarella works but melts flatter and doesn't have the same flavor punch. I wouldn't use parmesan here because it dries out on top of the Rotel. Stick with something that melts into a gooey layer.
My teenage son usually pushes fish around his plate until I give up and make him something else. He ate two pieces of this and then asked if there was more. I think it's the Rotel and cheddar that make it feel less 'fishy' to him, which, for a 15-year-old, is basically a miracle. I'd probably cut back the balsamic a little next time since it was slightly strong for my taste, but this is absolutely going back on the rotation.
The balsamic vinaigrette is what puts this ahead of every other quick cod recipe I've tried.
Five batches in and I still get a little excited when that balsamic smell hits while it's baking. The cod stays so tender at 425, never overcooked. Making it every spring from here on.
That balsamic smell at 425 gets my whole kitchen moving. Five batches and you're officially in too deep.
Balsamic on fish is not a combination I would have landed on myself. I've made cod enough ways to have a real opinion, and this had warning signs. The 10-minute bake at 425 does something, though. The vinegar completely softens, the Rotel brightens it, and the cheddar just ties it. Three weeks straight before I touched anything else.
I've made baked cod so many ways over the years. Was not expecting balsamic vinaigrette with Rotel and cheddar to be the version that beats them all, but here we are. The combo sounds random but it works in a way that's hard to explain, the tanginess and the heat and the cheese all kind of fuse together. I've gone back to this four times in the last month. My only tweak is I go a full 12 minutes because my cod runs thick.
Four times in a month. The 12 minutes is right for thick cod, I'd go 13 if you're getting pieces over an inch. And yeah, 'shouldn't work but it does' is exactly how I'd describe that topping combo.
Made this last week with some cod I picked up at the farmers market and the filets were pretty thick, closer to an inch. The 10 minutes at 425 had the cheddar perfectly golden but I wasn't totally sure the fish was done through (I always second-guess myself with fish). Is there a visual cue you look for, or do you just go by flake?
Stick a fork in the thickest part and wiggle it. If it flakes without resistance and the flesh is white all the way through, you're good. For a full inch, I'd go 12-13 minutes just to be sure.
I made this on a Wednesday when I had almost nothing in the fridge, and the Rotel and balsamic combination was not something I ever would have thought to put on fish. My daughter, who usually moves fish to the edge of her plate without touching it, finished hers and then asked if she could have some of mine. I don't think she even realized what she was eating. For a 4-ingredient dinner that bakes in 10 minutes, it felt like I had actually cooked something. I'd pile on a little more cheddar next time, but the fish came out tender and flaky and everything held together better than I expected for how quick it was. Four stars from a beginner who plans to keep this in the rotation.
The daughter detail got me. And yeah, more cheddar is right - I usually do closer to 3/4 cup now.
Batch cooked four servings on Sunday for the week and by Tuesday I was annoyed there was none left. The Rotel and balsamic combo holds up so well reheated (I was genuinely skeptical) and the fish doesn't get rubbery the way it does with other methods. Going to double it next time and stop pretending I have any self-control around this.
Ha, two days is a good run. If you double it use a 9x13 so the cod stays in a single layer. Stack it and it steams instead of bakes.
Tip for anyone whose Rotel makes the dish watery: drain it and then press it with a paper towel before you add it. The cheese melts so much cleaner that way, no pooling. I also swapped the sharp cheddar for pepper jack last time and it added real heat without changing the cook time at all. Cold weeknight, fish on the table in 15 minutes.
Some cans of Rotel are way wetter than others. Pressing makes sense. Pepper jack noted.
The recipe calls for 1 lb of cod but the video looks like 2, based on how full the pan is and number of pieces (1 lb for me was 3 pieces). Am I missing something?
I cut my cod in smaller pieces to get them to fit in the 8 x 8 inch baking dish. It was 1 pound.
But you could add more cod without adding more cheese or Rotel.
We had this last night and definitely will be making it again! And it was so easy to make! Thanks for all you do for the keto folks, Annie!
Four ingredients sounds too simple to actually be good. Still catches me off guard every time I make it.
Do you use the oil or butter to grease the baking dish for the Fiesta cod?
I used avocado oil but you could use either