Fiesta Baked Cod
Published May 8, 2022 • Updated February 17, 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 one-pot skillet lasagna and egg roll in a bowl, 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 secret here is balsamic vinaigrette doing all the heavy lifting. 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.
I love that this works on a busy weeknight the same way my 10-minute keto beef and broccoli does. No breadcrumbs, no garlic butter sauce, no panko crust. Just clean flavors and a dinner that’s on the table before anyone loses patience. If you’re looking for more keto seafood recipes, I have a whole collection, but this one is where I’d start. And if you want to try cod with a completely different flavor profile, my bacon wrapped cod is worth the extra step.
For other 5-ingredient keto recipes or easy keto dinner recipes, I’ve organized them so you can find something fast on those nights when you’re running short on time.
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 (Free) →Frequently Asked Questions
Can I use frozen cod fillets?
I use frozen cod for this recipe more often than fresh. I keep individually portioned packets in my freezer so I always have them on hand. Just thaw in a cold water bath for about 20 minutes before baking. I find frozen cod works just as well as fresh here.
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.
What internal temperature should baked cod reach?
I pull my cod out when it hits 145 degrees F on an instant-read thermometer. I stick the probe into the thickest part of the filet. If you don't have a thermometer, the fork test works. The fish should flake easily and look opaque white throughout.
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.
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!
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