Blackened Mahi Mahi

5 from 5 votes

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Blackened Mahi Mahi is a savory seafood dish that you can throw together in less than 15 minutes. It’s both healthy and tasty! With a delicious Cajun seasoning blend seared into a crispy, spicy crust, the textures and flavors are simply out of this world.

A plate of blackened mahi mahiwith rice and vegetables, with blackened Mahi-mahi

Blackened mahi mahi is an excellent meal any day of the week. This flaky Hawaiian fish is actually tremendously healthy, with plenty of lean protein and vitamins.  

Cooking mahi mahi doesn’t take much time at all. However, you should know — this is a rather smoky process! Keep your kitchen well ventilated while cooking.  

Between the paprika, pepper, and ginger, this dish has a great level of heat and spice, and the Cajun spice blend forms a delicious blackened crust. Serve with slices of lemon on a bed of fluffy white rice or alongside crisp or roasted vegetables.  

This seasoning blend actually tastes great on all kinds of seafood! I recommend trying it out with more of your favorites. My Pan Seared Ahi Tuna and Shrimp recipes, in particular, taste extraordinary.  

I also have just the thing for Marylanders who can’t get enough of that Old Bay taste —  my Old Bay Substitute!

Blackened Mahi Mahi on rice


  • Mahi Mahi – While it isn’t too fishy, it does have a distinctive flavor that could be described as sweet. It also has a firm texture that flakes deliciously when fried.
  • Butter -When blackening fish, you want to fry in melted butter to help quickly form the seasoned crust. I wouldn’t recommend using oil for this recipe.
  • Blackened Fish Seasoning -My Cajun seafood seasoning blend is versatile and can be used on almost anything. In addition to salt and black pepper, it contains:
    • Paprika – A versatile spice with a mild, smoky heat that can be used to season any protein.
    • Cayenne – This pepper has an iconic heat that is held in high esteem by spice lovers. Use it to spice up any dish.
    • Ground Ginger – Ginger adds another layer of spice, though it is not as severe as the peppers we use. It is also slightly sweet and goes well with seafood.
    • Oregano – Bitter and peppery, this has a distinctly earthy flavor.
    • Fennel Seeds – This seasoning is unique and is often paired with oregano and cloves. Also earthy, though more mild and warm.
    • Ground Cloves – Sweet and rich, with a hint of bitterness.
spices mahi mhi and melted butter


  1. Prepare the Fish.  Rinse lightly in running water. Pat dry with paper towels and dispose of the paper towels immediately to avoid spreading bacteria in your kitchen.
  2. Mix the Spices.  Combine the Cajun seasonings in a small bowl and set aside.
  3. Heat the Skillet.  Don’t add butter just yet! Heat the pan over high heat until it begins to smoke.
  4. Season. Smother the fish with melted butter and then dust with the seafood seasoning blend. Press the spices onto the filet to form an even crust and to help it stick.
  5. Sear.  Carefully place the filet in the hot pan and cook for 2-3 minutes on each side, until a dark crust forms and the center is cooked through.
  6. Serve.  Plate and serve immediately over a bed of fluffy steamed rice with fresh lemon.
overhead shot of Blackened Mahi Mahi with lemon and salad

How do you know when mahi mahi is done?

Any fish will flake easily when cooked thorough and go from translucent to opaque. When cooking mahi mahi, you may want to use a kitchen thermometer.   Insert the probe at an angle into the thickest part of the filet — when it reads around 135°F, it’s done! The temperature will continue to rise a few degrees as it rests.  

What does it mean to “blacken” a fish when cooking?

“Blackening” a fish just means to quickly sear it on either side. Frying at a high heat creates a crispy outer layer to contrast the flaky inside. It’s delicious, quick, and easy!  

What is the best way to prepare mahi mahi?

I’m partial to blackened mahi mahi, prepared by frying in butter. It takes about 15 minutes to prep and fry a 1 pound filet. When seared, you get an incredible seasoned crust and perfectly flaky fish in the quickest amount of time.   Alternatively, you could grill for 4 minutes on each side. If you prefer to bake your filet, then set your oven to 375°F and bake for 8 minutes.  

How long can I keep mahi mahi in the refrigerator?

Don’t refrigerate raw fish for longer than two days. Once the blackened mahi mahi is cooked, it should stay good for up to 4 days.   To reheat, bake at 325°F for just a few minutes. I wouldn’t recommend reheating on the stove, as it dries out fairly easily.

Blackened Mahi Mahi on plate with rice and beer in background

Other fantastic blackened dishes include:

For another blackened seasoning, try my Blackened Meat Seasoning. Enjoy!

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A plate of blackened mahi mahiwith rice and vegetables, with blackened Mahi-mahi

Blackened Mahi Mahi

5 from 5 votes
Blackened mahi mahi has a flavorful crust of spicy blackened fish seasoning. Make this simple mahi recipe for dinner in only 15 minutes!
Servings: 2
Prep: 5 minutes
Cook: 6 minutes
Total: 11 minutes


Cajun Blackening Seasoning


  • Rinse the fish and pat dry with paper towels.
  • In a small bowl mix together the spices and set aside.
  • Place a frying pan or cast iron skillet over high heat until it starts to smoke. Keep kitchen area well ventilated.
  • Toss the mahi mahi in melted butter and then coat with spice mixture on both sides. Press spice mixture to adhere.
  • Immediately sear on high heat 2-3 minutes per each side or until desired doneness is reached and center is cooked. Don’t overcook as it will dry out. Serve immediately with slices of lemon and steamed rice.


Other ways to cook Mahi Mahi – A quick grilling works 4 minutes per side as does popping it in a 375°F oven for 8 minutes.


Calories: 404kcal | Carbohydrates: 2g | Protein: 43g | Fat: 25g | Saturated Fat: 15g | Cholesterol: 227mg | Sodium: 404mg | Potassium: 970mg | Fiber: 1g | Sugar: 1g | Vitamin A: 1871IU | Calcium: 41mg | Iron: 3mg

The information shown is an estimate provided by an online nutrition calculator. It should not be considered a substitute for a professional nutritionist’s advice.

Course: Dinners
Cuisine: Southern
Have You Made This Recipe? Let Me Know on InstagramTag @keviniscooking or tag me #keviniscooking!
overhead of plate with rice and blackened mahi mahi on top with salad


Whether in the kitchen or on the grill, you’ll find me cooking American favorites with a love for BBQ, Mexican and Tex Mex. I’m passionate about making tasty food because life’s too short to be bland!

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  1. 5 stars
    I love blackened anything and this blackened seasoning works with almost everything but this fish was outstanding. Crispy, tender and delicious.

  2. 5 stars
    Going to give it a try tonight. My only problem with the recipe is that all my old salty fishermen buddies have always told me never NEVER rinse salt water fish with fresh water. They said it ruins the fish and have to follow their lessons as they have been fishing and grilling for 40+ years. I have never tried to blacken it so super excited, thanks for the recipe!

  3. 5 stars
    I order Mahi Mahi in restaurants all the time and have no idea why I never make it at home? Your blackened version has me inspired to do it immediately!

  4. 5 stars
    Blackened mahi happens to be one of my favorites Kevin! And I’m quite lucky because my husband Tom and several of our friends catch it fresh off and on all summer! Can’t wait to try your recipe!

    1. Oh boy, you have all the luck Mary Ann. What I love about fish dinners is they are so quick and typically easy to prepare and never fail to leave me smiling.