Blackened Mahi Mahi is an easy and flavorful way to enjoy a simple seafood dinner. Made with homemade cajun seasoning and quickly pan-seared, you can have this blackened fish on your table in less than 15 minutes.
What is Blackened Fish?
To blacken fish, or chicken, pork, or beef, is classically made by dipping the fish into butter, heavily seasoned with a variety of spices, and then seared in a very hot skillet.
Mahi Mahi is a great choice for blackened fish. Mahi Mahi is a firm-textured, mild white fish that is a great source of lean protein. It takes on flavors so well and is not at all fishy. In fact, if you think you don't like seafood, Mahi Mahi is a great fish to try.
My recipe for Blackened Mahi Mahi is made with homemade cajun seasoning and then pan-fried quickly. It is full of flavor, buttery, and flaky. Absolutely delicious and so easy to make.
What You Need
- Mahi Mahi: You want to select fish fillets that are about ½" thick and between 4 to 6 ounces each. You can use frozen, defrosted, or fresh mahi-mahi. While I love using mahi-mahi for this blackened fish recipe, as it is so mild and buttery in texture, you can use any firm white fish such as halibut, grouper, snapper, or seabass in place of the mahi-mahi.
- Cajun Seasoning: For the seasoning, I use a blend very similar to my homemade cajun seasoning. It is a bit spicy, so feel free to omit the cayenne pepper to control the level of heat.
- Butter: While most blackened fish recipes call for brushing the meat with butter before seasoning, I find that is unnecessary. Instead, I pan sear the fish with a mixture of oil and butter, which works to keep the fish moist while seasoning the fish.
- Oil: Use canola, avocado, or olive oil. The mixture of oil and butter will help keep the butter from burning.
- Lemon: Fresh lemon juice is a MUST to finish the fish. It will add acidity, moisture, and flavor.
How to Make Blackened Mahi Mahi
- In a small bowl, mix together the salt, paprika, garlic powder, onion powder, thyme, and cayenne pepper together.
- Pat the fish dry with paper towels. This will help the seasoning blend to adhere to the fish, giving it so much flavor.
- Sprinkle the cajun seasoning blend evenly over both sides of the fillets, rubbing the mixture into the fish with your hands to help the spice blend adhere to the fillets.
- Heat a large saute pan over medium-high heat and add the butter and oil. Once the butter is melted and the oil is hot, add the seasoned fish to the skillet, being sure to not overcrowd the pan.
- Cook, undisturbed, for 3 minutes, or until golden brown. Gently flip the fish over and continue to cook, undisturbed for an additional 3-4 minutes, or until the fish is browned on the opposite side, and opaque.
- Remove the fish from the skillet, and squeeze a wedge of fresh lemon over each fillet.
Serving Suggestions
- Serve the blackened Mahi Mahi with a side of cheesy grits and green beans almondine for a delicious, hearty meal.
- Cut or flake the cooked blackened fish into small bite-size pieces and serve in homemade tortillas with pineapple mango salsa for an incredibly delicious and quick Mahi Mahi taco.
- Serve the blackened fish on a homemade biscuit topped with coleslaw for an easy fish sandwich.
Storing Leftover Fish
Fish is best served immediately after preparation. However, if you happen to have leftover Mahi Mahi, store it in an airtight container in the refrigerator for up to 48 hours. Reheat in a dry skillet over medium heat for a couple of minutes per side, or until warmed through, and squeeze fresh lemon juice over the fish immediately before serving.
Recipe FAQs
To defrost frozen fish fillets, either place the frozen fillets in the refrigerator overnight OR place the frozen fillets, still in the packaging in a bowl of cold water in the refrigerator. It will only take a couple of hours for the fish to fully defrost this way. You also can opt to run the frozen fillets under cold water until defrosted, but I find this method to defrost the fish a bit unevenly.
Nothing compares to freshly caught fish. However, unless you live next to the ocean, it is really hard to find super fresh mahi-mahi. I personally opt for frozen mahi-mahi, as I know it is frozen at its peak freshness and will taste fresh without a fishy taste or smell when cooking.
The butter will add incredible richness and help the exterior of the flesh to become golden brown. However, if you are dairy-free simply omit the butter and sear the fish in 2 tablespoons of heated oil.
Yes! Jerk seasoning or Old Bay seasoning are great alternatives to the cajun blend of spices.
As prepared, this recipe is designed for 4 fish fillets. You can easily cut the recipe in half or double the recipe as desired.
More Easy Seafood Recipes
- Instant Pot Shrimp Boil
- Pan-Seared Tilapia
- Baked Salmon
- Grilled Shrimp
- Honey Garlic Salmon Sheet Pan Meal
If you enjoyed this simple recipe for Blackened Mahi Mahi, I would love for you to leave a comment and review below.
Blackened Mahi Mahi
Ingredients
Cajun Seasoning Mix
- 1 teaspoon kosher salt
- 2 teaspoons smoked paprika
- 2 teaspoons garlic powder
- 1 teaspoon dried thyme leaves
- ½ teaspoon onion powder
- ½ teaspoon cayenne pepper more or less to taste
Blackened Fish
- 4 mahi mahi fillets approximately 6 ounces each
- 1 recipe cajun seasoning approximately 2 tablespoons
- 2 tablespoons butter
- 1 tablespoon olive oil
- 1 lemon cut into 4 wedges
Instructions
- In a small bowl, mix together the salt, paprika, garlic powder, onion powder, thyme, and cayenne together.
- Pat the fish dry with paper towels. Sprinkle the cajun seasoning blend evenly over both sides of the fillets, rubbing the mixture into the fish with your hands.
- Place a large saute pan over medium-high heat and add butter and oil. Once the butter is melted and the oil is hot, add the seasoned fish.
- Cook, undisturbed, for 3 minutes, or until golden brown. Gently flip the fish over and continue to cook, undisturbed for an additional 3-4 minutes, or until the fish is browned on the opposite side, and opaque.
- Remove the fish from the skillet, and squeeze a wedge of fresh lemon over each fillet. Serve immediately.
Linda Dunneback
Can we grill this with the same
Results?
Kristen Chidsey
As long as you grease your grill really well. Fish is super delicate and can easily tear on the grill.
Elaine
Seafood is so intimidating for me - it's expensive and I'm always afraid I'll mess it up and it will be wasted. I'm ok with shrimp and salmon but your recipe is the first time I've tried making mahi mahi. It was a DELICIOUS hit! Thanks!
Kristen Chidsey
I am so happy you enjoyed so much Elaine!
Chris H
This was my first time making Mahi Mahi. Your recipe was super simple, easy to make and delicious. I paired it with brussell sprouts. My family will be enjoying this meal more often.
Kristen Chidsey
So happy to hear you enjoyed this recipe for Mahi Mahi, Chris! Thank you for sharing.
Lisalia
The best way to eat mahi mahi. I know you give some instructions for if we have leftover... but truly there was no leftover fish. Simply delicious - especially taken to the next level with that squeeze of lemon over top to finish it off!
Kristen Chidsey
I LOVE hearing that your family enjoyed so much! Thanks for sharing Lisalia!
Allyssa
Thank you so much for this recipe, it's really helpful and easy to make! Well done!
Kristen Chidsey
I am so happy you found the instructions easy to follow and you enjoyed the Mahi!
Beth
I love mahi-mahi and this is incredibly delicious! This has become one of my favorites for lunch or dinner. Such a great and flavorful recipe!
Kristen Chidsey
Thank you so for sharing Beth! So happy you enjoyed this recipe for Mahi Mahi!