Blackened Mahi Mahi

Flavorful Cajun spices seared onto a mild, firm fish make Blackened Mahi Mahi a taste sensation that’s easy enough for weeknights and special enough for company.

Blackened Mahi Mahi

Lately I’m trying to get more efficient in the kitchen.  ‘Cause sometimes it feels like my life is one big how did that take so long moment!

So recently I decided to go back to a quick and easy family favorite, Baked Mahi Mahi.  And since I was buying Mahi Mahi I bought a little more to make it blackened too!  Efficient right?  Plus I love the spicy but nuanced flavor of the classic dish! 

Everything came together even more when my blogging group decided to make southern recipes to share today (see below!).  Although not the classic definition of southern cooking, well, New Orleans is in the south.  And Mardi Gras is coming!

NOLA Balcony

What is Blackened Mahi Mahi?

It’s hard to imagine that before 1980, there were no blackened foods.  That was the year that New Orleans Chef Paul Prudhomme created his Blackened Redfish and started a movement.  Dipped in Cajun spices and seared, the flavorful seafood dish quickly spread and morphed to everything from chicken (see my Blackened Chicken) to shrimp (yes, I also do a  Blackened Shrimp).  

What is a blackened seasoning blend?

Blackened seasonings typically include cayenne, garlic, onion powder, oregano, thyme, paprika, salt and pepper.  The combo is nuanced and spicy without being mind-blowing.  True flavor.  And even better, they’re probably all in your spice collection already. 

I love not having to buy a new jar of spices!

What is Mahi Mahi?

Mahi mahi is a tropical or semi-tropical fish that is mild-flavored and firm.  And despite being nicknamed the dolphinfish, it is not the same as the dolphin which is an aquatic mammal.  The confusion comes from the name similarity but they are very different creatures–so you are not (emphasis not) eating Flipper!  

US Mahi mahi is considered an environmentally responsible seafood (see NOAA FIshwatch), but it does have moderate mercury levels, similar to chunk light canned tuna.  So consult a regularly updated source or medical professional for up-to-date consumption recommendations.

But otherwise it’s a healthy selection.  WebMD says that “Mahi mahi is a rich source of protein as well as vitamins B3, B6, and B12. Among minerals, it contains some magnesium, potassium, and phosphorus as well as good amounts of sodium and selenium.”

And it tastes good!

blackened mahi mahi

Why You’ll Love This!

Tasty.  Blackened foods are vibrant and flavorful!  That’s why they spread all over the country like wildfire!

Easy. This recipe consists of season and sear! It doesn’t get much easier than that!

Healthy.  You’ll need to be aware of the “moderate” level of mercury in mahi mahi and limit your intake accordingly. But as long as you consume it in moderation, you’ll be eating a delicious fish that’s lean and high in protein.  

What You’ll Need

Ingredient Notes

  • Cajun Seasoning.  Cajun seasoning mix or paprika, cayenne pepper, dried thyme, dried oregano, garlic powder, onion powder, black pepper and salt.
  • Mahi mahi filets.  This mild firm fish is excellent blackened.
  • Non-stick spray.  This keeps the fish from sticking to the pan
  • Butter (optional).  This is optional but can add flavor.

Special Tools

  • A stainless steel or cast iron skillet is good since you are searing at a high temperature.

Step by Step Directions

Mix spices (or pour a premade Cajun spice mix ) in a bowl.

cajun spices in bowl

Heat up a cast iron or other high heat skillet.  Coat fish with seasoning mix.

season fish

Sear first side using non-stick spray.

sear fish

If you’d like you can finish searing with butter, but this is optional (and will smoke up your kitchen more).

finish with butter (optional)


Searing in butter versus oil

Traditionally blackened dishes are seared in butter. After all there’s nothing quite like the flavor of browned butter!  In a restaurant with high intensity range hoods, or on the grill, this poses little problem. 

But for the home cook, especially in a house all buttoned up for winter, it is more of an issue.

I initially solved the problem by omitting the butter and using a non-stick spray.  This let me cook on high heat with minimal concern about filling the house with smoke. This time I decided to try something new.  I cooked the first side using the non-stick spray but added the butter when I flipped the fish. 

I think this is a good compromise, but truly, it’s delicious either way!

Blackened mahi mahi

How to Serve

This dish is quick enough for a weeknight dinner or special enough for company—how good is that!

I love to keep with a Cajun theme when I serve this. Nice sides include:

    • Okra
    • Red beans & rice (I used a packaged mix)
    • Salad w remoulade dressing (see my NOLA Fried Oyster Salad)
    • Coleslaw
    • Cornbread
    • Dirty rice

And while this can be served as an entree, it also works beaurifully as part of other entrees.  Top a salad for a Blackened Mahi Salad with Remoulade dressing.  Cut it thinner and insert into a bun for a Blackened Mahi Mahi Sandwich (use a remoulade here too)!  And don’t forget Blackend Mahi Mahi tacos!

Blackened mahi mahi


Store any leftovers in the refrigerator and use within a few days.  This can also be frozen.

Tips & FAQs

While most mahi mahi will have the bloodline removed, if you notice a dark line down the middle of your fish, cutting it out is recommended, since it may taste “fishy”.

Can I use pre-mixed Cajun spices?  Yes, you can.  Depending on how often you make blackened dishes, you might want to consider if the convenience is worth it.  (Then it will take you like 30 seconds to prep!)

Blackened mahi mahi

Southern Food

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Blackened Mahi Mahi

Blackened Mahi Mahi

Flavorful Cajun spices seared onto a mild, firm fish make Blackened Mahi Mahi a taste sensation that's easy enough for weeknights and special enough for company.
Author: Inger
5 from 6 votes
Prep Time 5 mins
Cook Time 10 mins
Course Main Dish
Servings 4
Calories 180 kcal


  • 1 ½ pounds mahi mahi filets 4-5 fillets
  • Non-stick cooking spray or oil for frying
  • 1 Tablespoon butter optional

Blackened Seasoning Mix

  • 2 teaspoons paprika
  • 1/4 teaspoon cayenne pepper
  • 1 teaspoon dried thyme
  • 1 teaspoon dried oregano
  • 1 teaspoon garlic powder
  • 1 teaspoon onion powder
  • 1/2 teaspoon black pepper fresh ground


  • Start cast iron skillet heating over medium high heat
  • Mix seasoning ingredients together. Sprinkle seasoning onto both sides of mahi mahi
  • When pan is very hot, spray with PAM non-stick spray. Add fish to pan. Turn when charred (about 3 minutes). Cook until both sides are charred and cooked through. Optionally add a Tablespoon butter when you turn the fish.
  • Serve immediately.


Calories: 180kcalCarbohydrates: 2gProtein: 32gFat: 4gSaturated Fat: 2gPolyunsaturated Fat: 0.5gMonounsaturated Fat: 1gTrans Fat: 0.1gCholesterol: 132mgSodium: 174mgPotassium: 759mgFiber: 1gSugar: 0.2gVitamin A: 958IUVitamin C: 0.4mgCalcium: 45mgIron: 3mg
I am not a health professional and nutrition data is calculated programatically. Accuracy may vary with product selection, calculator accuracy, etc. Consult a professional for the best information.
Tried this recipe?Let us know how it was!

14 thoughts on “Blackened Mahi Mahi

  1. Angela

    Thank You for this recipe! I made it for lunch today, my husband and I both think it tastes delicious!!

    1. Inger Post author

      Yes, i think Cajun seasonings are amazing too! And love that this recipe is also really easy, as a bonus!

  2. Christie

    We have been blackening fish for a long time. Well before Emeril was even popular. Mahi mahi is one of my fave fishes. This is going on the menu soon.

  3. David Scott Allen

    I really need to try both your Mahi Mahi recipes — I just made a new batch of my Cajun seasoning (sans G) for Mardi Gras! I have to admit that I have never had Mahi Mahi, but I saw it the other day at the fish market and it is much more reasonably priced than other fish — another great bonus in using it!

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