A homemade Cajun spice mix adds incredible flavor to this Blackened Mahi Mahi. It’s a quick dish you can easily pull together on a busy weeknight but it’s so tasty you’ll want to serve it to guests!
This is a new recipe for me and it came about after Paul and I had a meal at a nearby restaurant. We both ordered the mahi mahi special that was served with mashed sweet potatoes and veggies, and then we basically freaked out about how good it was for at least two days after and it haunted us in our dreams…. we’re weird.
This all had me wondering why the heck I never make mahi mahi at home. So, of course, I had to make some mahi mahi.
I set out to capture the same flavors we had in the restaurant dish and knew I definitely had to pair it with sweet potatoes, just like they did. The sweetness perfectly complements the slightly spicy fish in a soul-satisfying way. It’s truly a perfect flavor combination and it also happens to be SO good for us.
Say hello to my new favorite item from Costco. This great big package of Wild Caught Mahi Mahi contains skinless, individually vacuum-packed portions of incredibly fresh mahi mahi. I pop this bag in my freezer and pull just the number I need. The fish is FRESH, people. There is zero fishy aroma in the house after cooking it.
Mahi Mahi is a mild, firm textured white fish that is wonderfully tender – almost buttery – when prepared properly. It’s a fabulous source of lean protein and packed with nutrition. If you’ve got young ones who are squeamish about seafood, this would be a great one to try on them. Yes, blackened fish can be quite spicy. but when you make your own spice mix you get to decide precisely how spicy you’d like it. I’ll show you how!
To make the Kickin’ Cajun Seasoning Mix, grab a small bowl and combine 1½ teaspoons onion powder – 1 teaspoon each of smoked paprika, oregano, granulated garlic or garlic powder, thyme, and salt – and ½ teaspoon each of black pepper and cayenne pepper. The only spicy item here is the cayenne so feel free to adjust the amount to suit your taste. At ½ teaspoon, the fish will be mild to moderate on the spice scale. I’m a bit of a wimp and it is perfect for me. If I had little ones, I’d reduce it to ¼ teaspoon or even eliminate it all together. My big boys would tell me to add more!
Update – By popular demand I’ve published a recipe for a big batch of the Kickin’ Cajun Seasoning Mix. Check out the post for other delicious ways you can use this flavor-packed blend.
If you are using frozen mahi mahi, be sure to allow it to thaw completely (24 hours) in the refrigerator. Pat the fillets dry with paper towels so the spice mix will adhere nicely.
Sprinkle both sides of the fillets with the spice mix and use your clean hands to pat the mixture into the flesh of the fish. Then, of course, wash those hands again.
Melt 2 tablespoons butter and 1 tablespoon olive oil in a large skillet over medium-high heat. Get the pan as hot as it can get, without burning the butter, and then add the seasoned mahi mahi. You want that nice sizzle when the fish hits the pan. Cook it a good 3 or 4 minutes on one side until nicely golden brown, then flip it and let it go a few minutes on the other side. You don’t want to overcook it so be vigilant and pull the pan off the heat just as soon as it’s cooked through and flakes easily with a fork.
Remove the fish to a serving platter and squeeze fresh lemon juice over the top. A little citrus is a necessary thing when cooking fish as far as I’m concerned.
Oh, and before I go, if you’d like to serve this with mashed sweet potatoes, here’s how I did it. Place a couple of red-skinned sweet potatoes in a large pot and cover with water. Bring to a boil, reduce the heat and bring the water to a nice simmer and cover the pot. Cook the potatoes for 45 minutes to an hour, or until they pierce easily through with a knife. Remove from the pot to cool for just a couple of minutes. Use paper towels to pull the skin off and then mash the potatoes with a touch of light sour cream and salt. Perfect every time.
If you love mahi mahi, be sure to check out my Mahi Mahi with Lemon Butter Sauce. It has an entirely different but utterly delicious flavor profile.
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Blackened Mahi Mahi
Ingredients
- 4 mahi mahi fillets, approximately 6 ounces each
- 2 tablespoons butter
- 1 tablespoon olive oil
- 1 lemon
Kickin’ Cajun Seasoning Mix:
- 1 ½ teaspoons onion powder
- 1 teaspoon garlic powder
- 1 teaspoon smoked paprika
- 1 teaspoon dried thyme leaves
- 1 teaspoon dried oregano leaves
- 1 teaspoon fine grain sea salt
- ½ teaspoon freshly ground black pepper
- ½ teaspoon cayenne pepper, or to taste
Instructions
- Combine all Kickin’ Cajun Seasoning Mix ingredients in a small bowl.
- Pat fillets dry with paper towels. Season the fillets liberally with Kickin’ Cajun Spice Mix on both sides, pressing the seasoning into the fish with your hands. Wash hands thoroughly.
- Place a large saute pan over medium-high heat and add butter and oil. When the fat is nice and hot, add the seasoned fish. Cook, undisturbed, for several minutes, until golden brown on one side. Flip fish over and continue to cook until opaque and completely cooked through.
- Squeeze lemon juice over the fish and serve.
Video
Notes
Nutrition
Nutrition information is automatically calculated using generic ingredients, and is an estimate not a guarantee. For more accurate results, please refer to the labels on your ingredients at home.
Excellent recipe!! Easy-Peasy, fast & delicious!!
I do not eat fish. Too fishy tasting. But this mahi recipe is a 5 star in my book. Thank you so much!
You’re very welcome, Jana. So glad you liked it!
Great and so very easy. We were looking for recipes that have lots of flavor to keep the fish from being too bland. This was perfect. Thanks!
Thank you so much for sharing this recipe. My husband loves spicey hot seasonings and while I like spicey, I like to be able to taste the seasonings, not just hot. My husband said this is the best cajun seasoning he has had and I loved it too. Just the right mix. Win win for us.
Delicious! Just perfect. I, too, just came home with the big bag of Mahi Mahi from wonderful Costco and wasn’t sure which direction to go. Salmon has been our go-to for years and I wanted to switch it up. The spice seasoning is so great, dinner was amazing. I did one side on the med-high, flipped and lowered to medium to prevent butter burn and too much blackening. Thank you!
Fantastic! We love this seasoning on salmon too so you might want to give that a try if you are salmon fans.
WOW! This was delicious….just the right amount of heat. My 11 year old daughter even loved it! Served with cauliflower mashed potatoes and roasted Brussels sprouts! AMAZING!
Frozen fish is not “FRESH'”. I despair. But Mahi Mahi is lovely. Especially fresh!
Hi Peter. If you have access to fresh mahi mahi you can absolutely use this recipe and I’m sure it will be wonderful. The wild caught frozen mahi mahi from Costco is a high quality option that we love.
I picked up some fresh mahi at a local fresh air market this morning. After looking over a few recipes, your’s was the one I was looking for. I wasn’t disappointed, even though I had to omit the cayenne to suit my wife’s bland preferences.
This was very good. The spice combination accented the mahi perfectly. Best of all, Elaine ate all of her fish and complemented the recipe, something she almost never does (eating all the fish, that is).
Except for the cayenne, and using some ghee instead of butter, I followed your recipe as written. I’ll serve it to guests next time.
The recipe sounds great – we’ll try it. We get the same Mahi Mahi from Costco. It’s wonderful. I usually grill it on my charcoal Weber.
Made this for my husband – he loved it so much that I made it again two days later. (Mahi was on sale at local grocer in South Carolina.) I don’t go crazy for blackened anything but I may have to try it myself – without red pepper/chili powder (I did not have cayenne) because he was so thrilled. I made the sweet potatoes too – that was perfect and he thought he didn’t like sweet potatoes that much – now he loves them. Thank you.
My husband thought he hated sweet potatoes when I met him too and he was quickly convinced otherwise! I hope you are doing well there in South Carolina through all of this scary weather. Thanks so much for your comment, Donna. 🙂
I had no idea how to cook mahi mahi so I decided to look up a recipe. This is now my favorite fish! It was delicious! My husband was shocked at my “skills” and agreed that it tasted like a dish from a gourmet restaurant! Thank for this simple and easy recipe. It’s now my “go to”!
Great spice mix! I’m big on heat so tossed in a little more of the cayenne and added chili powder also. Needed some inspiration for the mahi sitting in my freezer and just so happened to already have been making mashed sweet potatoes. This was great, and I’ll definitely make it again. Thank you!
This was an awesome recipe! My husband is a picky eater & he ate everything. Thank you. Looking forward to checking out more of your recipes.