This baked mahi mahi gets its Mediterranean flavor from a briny tomato, olive and caper sauce. It goes on before the fish bakes and bastes it the whole time, so it never dries out.
Why This One Works
The olives and capers are what set this apart from a basic baked fish dinner: a salty, briny depth that canned tomatoes alone can't get to on their own.
It's also the dinner I reach for when I want to serve fish to guests without babysitting the stove all night, and a solid place to start if cooking fish still makes you nervous. Mahi mahi is a mild fish, not "fishy," so it's forgiving on flavor, and the sauce does the rest.
This one's a weeknight fish dinner, done in about 40 minutes start to finish. The sauce can be made up to two days ahead if you want a head start.
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What I Learned Making This Recipe
Fish intimidates a lot of home cooks. It's easy to overcook, and hard to judge just by looking at it. The sauce was my fix: spoon it over the fish before it bakes, and the fish is never sitting directly in dry heat. That buys you some room for error.
I still keep an instant read thermometer by the oven for this one, though. Mahi mahi is done at 137°F, and pulling it the second it hits that number is the difference between flaky and rubbery.
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Five Star Review
⭐️⭐️⭐️⭐️⭐️
"My son and I made this a few weeks ago and we loved it! We didn't use olives because my son doesn't care for them, but we used extra capers. Also added feta cheese, which was an excellent addition! A few days later we used the extra sauce over pasta which was also delicious! Looking forward to making this again next week!"
- Karen
Ingredients & Substitutions
- Mahi mahi fillets. Fresh or frozen both work. If you're using frozen, thaw it overnight in the fridge and pat it dry before you start; a wet fillet waters down the sauce. Can't find mahi mahi? Cod and halibut are both good substitutes.
- Canned cherry tomatoes. A 14-ounce can of whole cherry tomatoes gives the sauce a rustic, chunky look. Canned diced tomatoes are a fine substitute if you can't find whole cherry tomatoes, though the sauce comes out a bit thinner.
- Kalamata olives. These bring most of the brine. Swap in Castelvetrano olives if you want something a little different: they're buttery and milder than Kalamatas, and still give the sauce its olive backbone. Coarsely chop whichever one you use so they distribute through the sauce.
- Capers. They add a second, smaller hit of brine on top of the olives, so you get a little pop of it in almost every bite.
- Dry white wine. A dry white like Sauvignon Blanc adds acidity to the sauce as it reduces. Skipping the alcohol? Vegetable or chicken broth works in its place.
- Fresh parsley. Worth using fresh here, not dried. It keeps the sauce tasting bright instead of muddy.
- Crushed red pepper. The recipe gives a range, ¼ to ½ teaspoon, so you can dial the heat up or down depending on your tolerance.
How to Make It
Season The Fish
Place your fish in a glass or ceramic casserole dish. Pour lemon juice over top of fillets and season with salt and pepper. Set aside for 10 minutes while you make the sauce.
Build The Sauce
Sauté the onions in a pan until translucent. Add garlic and wine and cook until wine is reduced by about half. Add remaining ingredients to pan (tomatoes, olives, capers, parsley and spices) and stir to combine.
Bake
Spoon sauce over fish and bake 15-25 minutes, or until fish flakes easily and reaches 137°F. Serve over rice or orzo, ladling extra sauce on top.
Before You Make This
Use glass or ceramic, not metal. The lemon juice you pour over the fish is acidic, and acidic marinades can react with metal pans, giving the fish a metallic taste. Stick with glass or ceramic for both marinating and baking.
Pat frozen fish dry. If you're using frozen fillets, thaw them overnight in the fridge, then pat them dry before seasoning. Extra moisture on the fish waters down the sauce as it bakes.
Use an instant read thermometer. Mahi mahi is done at 137°F: opaque and flaking easily with a fork. Doneness depends on how thick your fillets are, so checking with a thermometer is more reliable than going by time alone.
Start checking at 15 minutes. The bake time is a 15-25 minute range on purpose, since fillet thickness varies. Checking early keeps you from overshooting the temperature and drying out the fish.
Serving Suggestions
Rice or orzo are the classic pairings here, both good at soaking up extra sauce. Couscous works too, and a few readers have ladled the sauce over pasta instead, which works fine if that's what's already in the pantry. If you want a side that doesn't compete with the sauce, try Lisa's Arugula Salad. It's a good match: bright and acidic against all that briny olive and caper flavor.
Make Ahead & Storage
You can make the tomato sauce up to 2 days ahead. Store it in the fridge and reheat it before spooning it over the fish, so it doesn't cool the dish down right as it goes into the oven.
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Recipe
Baked Mahi Mahi with Tomatoes and Olives
Ingredients
- 1.5 pounds mahi mahi, skinned and cut into 4 fillets
- 1 lemon, juiced
- 1 tablespoon olive oil
- 1 medium onion, peeled and chopped
- 2 cloves garlic, minced
- ½ cup dry white wine (or vegetable broth)
- 1 (14 oz) can cherry tomatoes
- ½ cup coarsely chopped Kalamata olives
- ¼ cup chopped fresh parsley
- 2 tablespoons drained capers
- ½ teaspoon dried oregano
- ¼-1/2 teaspoon crushed red pepper, depending on your spice tolerance
- kosher salt and pepper
- Cooked rice or orzo
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Instructions
- Place mahi mahi fillets in a glass or ceramic casserole dish (no metal). Season with salt and pepper. Pour lemon juice over fillets and let stand for 10 minutes.1.5 pounds mahi mahi, , 1 lemon, , kosher salt and pepper
- Meanwhile preheat oven to 375° F.
- Heat oil in a large skillet over medium heat. Saute onions until almost translucent. Add garlic and cook for 30 seconds. Add wine to pan and cook until liquid is reduced by half (about 3-4 minutes).1 tablespoon olive oil, 1 medium onion,, 2 cloves garlic, , ½ cup dry white wine
- Add tomatoes, olives, parsley, capers, oregano and crushed red pepper to skillet and stir to combine. Season to taste with salt and pepper.1 (14 oz) can cherry tomatoes, ½ cup coarsely chopped Kalamata olives, 2 tablespoons drained capers, ¼ cup chopped fresh parsley, ½ teaspoon dried oregano, ¼-1/2 teaspoon crushed red pepper,
- Ladle tomato mixture over fish in casserole dish making sure each fillet has sauce on top of it. Bake for 15-25 minutes or until fish reaches 137°F.
- Serve immediately over rice or orzo, ladling extra sauce on top.Cooked rice or orzo
Notes
- You can use fresh or frozen fish in this recipe. If using frozen, defrost overnight in the refrigerator. Pat fish dry before using.
- Look for fish fillets that are about 1" thick and about 6 ounces each.
- Can't find mahi mahi? Substitute cod or halibut instead.
- Canned cherry tomatoes look beautiful in the rustic sauce, but if you can't find them, substitute canned diced tomatoes. The sauce will be slightly thinner with diced tomatoes.
- Avoiding alcohol or don't have any wine in the house? You can use vegetable or chicken broth instead.
- Check the fish after 15 minutes of cooking time and add time if needed. Doneness will vary depending on the size of your fillet. Mahi Mahi is cooked through at 137°F. It will be opaque and flake easily with a fork. The sauce somewhat insulates the fish from overcooking but I recommend using an inexpensive instant read thermometer to pull the dish from the oven the moment it's cooked through.
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Nutrition
Nutrition info not guaranteed to be accurate.
Norma says
Very delicious. We will be cooking fish this way more often.
Karen Kearns says
My son and I made this a few weeks ago and we all loved it! We didn't use olives because my son doesn't care for them, but we used extra capers. Also added feta cheese which was an excellent addition! A few days later we used the extra sauce over pasta which was also delicious! Looking forward to making this again next week!
Anne C. Marsh says
Made this tonight with fresh little tomatoes (mix of cherry, grape, yellow, and orange) cut in half or in quarters,.depending on size. Also only had two mahi mahi fillets so LOTS of sauce for the fettuccine over which I served it. This is delicious and is already in the rotation for li'l ol' single me. Thank you!
So glad you enjoyed the recipe, Anne. Thanks for stopping back and sharing your experience with the rest of the GWL community!
Jeanne Stanton says
This was AMAZING!!! We all LOVED it and I'm making it again tonight. I'm going to serve it on top of a bed of my arugula and I'm adding dill and topping with feta this time. The BEST mahi mahi I have ever eaten! Thank you for the recipe!
Hi Jeanne, so glad you enjoyed it! Thanks for stopping back to share your review with others in the GWL community.
Kathy Harsen says
Can’t wait to make this! Can I use Kalamata olives?
Absolutely!