You will swoon over this easy recipe for the Best Ever Blackened Mahi-Mahi. Coated in a homemade cajun blackened seasoning mix and pan-seared in a screaming hot cast-iron skillet, these mahi-mahi fillets are moist with a crispy, spicy, flavor-packed crust!
Like my recipes for zesty Blackened Grouper, Buffalo Shrimp, and Blackened Cod, this recipe is incredibly delicious and simple to prepare. And the best part is you can have this fantastic seafood entree on the table in ten minutes.
Blackened mahi-mahi is a restaurant-style main dish that’s as perfect for a quick weeknight dinner as a dinner party.
With firm, white, lean flesh that is slightly sweet and very mild, mahi-mahi is a versatile fish that is tasty whether it’s prepared blackened, fried, baked, pan-seared, broiled, or grilled. Plus, cooking it couldn’t be easier!
Jump to:
- Ingredient notes:
- How to make blackened mahi-mahi:
- Top tip:
- What is mahi-mahi:
- What does it taste like:
- Side dishes that pair well with this recipe:
- What does “blackened” mean:
- What is “blackened” seasoning:
- Recipe variations:
- Frequently asked questions:
- More tips and tricks:
- More recipes using blackened seasoning:
- 📋 Recipe:
Ingredient notes:
(Specific measurements can be found in the recipe below.)
- Fresh mahi-mahi – skinned and cut into fillets. You can use frozen mahi-mahi, which must be thawed and dried with a paper towel before cooking. Any firm white fish such as halibut, grouper, snapper, redfish, Corvina, or seabass make a suitable substitute.
- Butter – coats the fish to help the seasoning stick and adds a rich flavor to the overall dish.
- Fresh lemon juice – there is a scientific explanation, but the best reason is that it enhances the flavor of fish.
To make the blackened seasoning, you will need:
- Cayenne and black pepper – provide a bit of heat.
- Oregano, thyme, and cumin – provide a herby, earthy, smoky taste.
- Garlic and onion powder – lend their unique flavors to the mix.
- Paprika – adds a bit of color and smokiness.
- Brown sugar – adds just a touch of sweetness that complements the savory spices.
- Kosher salt: enhances all of the flavors and brings everything together.
How to make blackened mahi-mahi:
- Combine all blackening seasoning ingredients in a bowl and mix well. Store any leftover seasoning mix in an airtight container for future use.
- Use a paper towel and pat dry the fillets.
- Melt two tablespoons of butter. Use a pastry brush and coat both sides of the fillets.
- To season the mahi-mahi, top each fillet with a tablespoon of the blackening spice mix and rub it in with your fingers. Then, flip the fillet over and do the same thing on the other side.
- Add three tablespoons of butter (you can substitute olive oil) to a cast-iron skillet over medium-high heat.
- Set your exhaust fan to high. Blackening fish will produce smoke. When the butter melts, and the skillet is hot, add the fish and let cook undisturbed for three minutes.
- Use a fish spatula or pancake turner and turn the fillets over. Cook for another three to four minutes. You can tell when fish is cooked when the flesh turns from translucent to opaque and flakes easily when pierced with a fork. Be careful not to overcook.
- Serve the blackened mahi-mahi hot with a squeeze of lemon juice over the top, or see my other suggested toppings in the “recipe variations” section below.
Top tip:
For the most authentic flavor and crunch, use a cast-iron skillet to blacken your fish. Of course, a heavy-duty non-stick skillet works too, but you might not get the crispy exterior.
What is mahi-mahi:
Closely related to pompano and second only in beauty to red snapper with its gorgeous red coloring, mahi-mahi is one of the most stunning fish in the world, with iridescent blue, green, and gold coloring.
Mahi-mahi is found in warm waters worldwide, including the Gulf of Mexico, and is also called dolphin, dolphinfish, or dorado. But don’t worry; it is unrelated to Flipper or bottlenose dolphins, which are mammals.
What does it taste like:
Mahi-mahi has a mild, slightly sweet flavor with a firm, moist texture. The flesh is lean and tender with large flakes. When cooking mahi-mahi, it’s delicious whether blackened, broiled, baked, grilled, or fried.
Side dishes that pair well with this recipe:
If you want to serve this dish over rice, this recipe for Tropical Island Rice would be lovely. Or you could serve the blackened mahi-mahi with Cheese Grits or Cheese Grits Casserole, coleslaw, and Hoe Cakes or Hush Puppies.
It would also be delicious served with dirty rice, southern spicy tomato cheese grits or southern corn casserole, twice-baked sweet potatoes, green beans with new potatoes, southern potato salad, or deviled eggs.
Panzanella, Southern Cucumber and Tomato Salad, or my Summer Pasta Salad would also nicely round out your menu.
What does “blackened” mean:
Blackening fish is simply coating it with a blend of blackened spices and searing it quickly over high heat in a cast-iron skillet until the spices are caramelized and form a deliciously tasty crust.
While most folks blacken their fish in a cast-iron skillet over a burner on the stove, you can also blacken it outside on a grill, blacken it in the oven, blacken it in an air fryer, and even blacken it under a broiler.
What is “blackened” seasoning:
Blackening seasoning gives the mahi-mahi fillets their flavorful spicy taste, blackened crusty appearance, and delicious crunch. My easy homemade cajun blackening seasoning recipe contains spices, including oregano, thyme, and cumin. I also include a touch of brown sugar and a little cayenne pepper for heat.
This delicious blackening seasoning mix can also be used on shrimp, chicken, beef, and pork. I’ve even been known to add a little to soups, stews, and various sauces. You can also substitute it for cajun or creole seasoning in recipes. I always make extra and keep a jar in my pantry.
You can also purchase pre-made blackened seasoning, and you should be able to find it in your grocery store’s spice aisle.
I like and have used both Old Bay Blackened Seasoning and Chef Paul Prudhomme Blackened Redfish Magic. Prudhomme was a chef from southern Louisiana credited with popularizing blackened seasoning and creole and cajun seasonings.
Recipe variations:
- While blackened mahi-mahi is delicious on its own, if you are like me and switch things up occasionally, try topping the fillets with a cajun cream sauce or lemon butter sauce.
- It is also delicious when topped with the cool fresh taste of mango salsa, peach salsa, pineapple salsa, avocado salsa, or cucumber salsa.
- Blackened mahi-mahi can also be served in tacos, wraps, and sandwiches such as po’ boys. In addition, it can be added to pasta, substituted for shrimp in shrimp and grits, and makes an excellent and healthy topping for caesar salad.
Frequently asked questions:
According to the Florida Department of Agriculture, when shopping for mahi-mahi, “look for firm, slightly pink meat with a fresh sea-breeze aroma and no discoloration.”
Fresh fish can be stored covered in your refrigerator for up to two days. If you need to store it longer, you should freeze it. To freeze fish, wrap tightly to prevent freezer burn. It will keep frozen for up to two months. Thaw overnight in the refrigerator before cooking.
Mahi-mahi has a thick skin that will prevent the blackening seasoning from reaching the flesh. Therefore, it should be removed for this recipe, or you can ask your fishmonger to remove it.
Mahi-mahi, like bluefish and Spanish mackerel, naturally have a bloodline (darker red flesh) running down the length of the fillets.
Most of the time, when you purchase fillets, it has already been removed. If not, you will want to cut that out. While a bloodline is safe to eat, it has a stronger taste and can make your fillets taste fishy.
This dish cooks quickly and is best when eaten right after cooking. However, you can make the blackened seasoning well ahead of time.
Fish cooks quickly and should be watched carefully. It is done when the flesh turns from translucent to opaque and flakes easily when pierced with a fork. The final internal temperature should be 140 °F as measured by an instant-read meat thermometer.
Leftovers can be stored covered in the refrigerator for up to three days. The fillets can be reheated in a skillet with a bit of oil or butter over medium heat for five to ten minutes.
My favorite way to repurpose leftover fish is by using it to make tasty Fish Cakes.
More tips and tricks:
- To make this recipe on a grill, preheat your grill to high, add your cast iron skillet, preheat it, and follow the directions for cooking it on the stove. The advantage of cooking it outside is that you won’t have a smoky kitchen if you don’t have a good exhaust fan.
- The recipe for blackened seasoning, as written, is a little spicy. If you want to reduce the heat, reduce the amount of cayenne pepper, or eliminate it.
- Fresh fish can be stored covered in your refrigerator for up to two days. If you need to store it longer, you will need to freeze it. To freeze fish, wrap tightly to prevent freezer burn. It will keep frozen for up to two months.
- Thaw frozen fish overnight in the refrigerator before cooking, and pat it dry before adding the butter or seasoning.
- When buying fish fillets, plan on approximately 4 to 6 ounces per person and try to get the fillets the same size and thickness so they will cook in the same amount of time.
- You can substitute purchased blackening seasoning for the homemade. I like and have used Old Bay and Paul Prudhomme blends.
- The cooking time shown in this recipe is for fillets that are one-half of an inch thick. If your fillets are thinner or thicker, they will take less or more time to cook properly.
- If you are on a low-carb diet, eliminate or reduce the amount of brown sugar in the seasoning mix.
More recipes using blackened seasoning:
Here are a few more menu ideas featuring seafood as the main ingredient:
- Grilled Grouper with Sweet and Spicy Mango Salsa
- Pan-Seared Red Snapper with Mango Salsa
- Crispy Oven-Baked Grouper
- Pan-Seared Grouper with Gremolata
- Oven-Baked Parmesan Grouper Fillets
- Southern Blue Crab Cakes
- Fried Oysters
- Pan-Fried Shrimp
If you need more recipes using fish or shellfish, here is a link to all of my seafood recipes.
⭐️⭐️⭐️ ⭐️ ⭐️ If you make this recipe, please leave a comment and give it a star rating. I would love to know how you liked it!
Thank you so much for visiting Grits and Pinecones!
📋 Recipe:
Best Ever Blackened Mahi-Mahi Recipe
Equipment
- fish spatula or pancake turneer
- cast iron skillet or heavy duty non-stick skillet
Ingredients
- 4 mahi-mahi fillets, 4 to 6 ounces each, skinless, about a half-inch thick
- 5 tablespoons unsalted butter, divided
- 1 lemon fresh
Cajun Blackening Spice Mix:
- 2 teaspoons paprika
- 1 teaspoons cayenne pepper
- ½ teaspoon ground black pepper
- ½ teaspoon dried oregano
- ½ teaspoon ground dried thyme
- ½ teaspoon ground cumin
- 1 teaspoon garlic powder
- 1 teaspoon onion powder
- 1 teaspoon brown sugar
- 2 teaspoons kosher salt
Instructions
Cajun Blackening Spice Mix Directions:
- Combine all blackening spices in a bowl to mix the seasoning. Store any leftover seasoning mix in an airtight container for future use.
Blackened Mahi-Mahi Directions:
- Use a paper towel and pat dry the fillets.
- Melt two tablespoons of butter. Use a pastry brush and coat both sides of the fillets.
- Top each fillet with about a tablespoon of the blackened spice mix and rub in with your fingers. Flip over and do the same thing on the other side.
- Add three tablespoons of butter (you can substitute olive oil) to a cast-iron skillet over medium-high heat.
- Set your kitchen exhaust fan to high. Blackening fish will produce smoke. When the butter is melted, and the skillet is hot, add the fish and let it cook undisturbed for three minutes.
- Use a fish spatula or pancake-turner and turn the fillets over. Cook for another three to four minutes. You can tell when fish is done when the flesh turns opaque and flakes easily when pierced with a fork. Be careful not to overcook.
- Serve the blackened mahi-mahi hot with a squeeze of lemon juice over the top.
This was amazing! So fancy but so easy!! Loved the addition of brown sugar to spice rub, Thank you!
This came out so good tonight! I can’t wait to make it again! So yummy!
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