Blackened Ahi Tuna
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Blackened ahi tuna is so buttery and tender that it literally melts in your mouth. Tuna is fresh and delicious as-is, so just imagine how mouthwatering it tastes coated in traditional Cajun blackening seasoning. These juicy tuna steaks have a 5-star taste… but take just 10 minutes to make!
To me, summer means seafood. And while fish tacos, salmon, and shrimp are all well and good, sometimes I want something really fresh and special. Enter blackened ahi tuna!
It’s a super quick recipe that you make right on the stovetop in just 10 minutes, no warm weather or grill required, just ventilate well!
I think people are hesitant to cook with raw ahi tuna because they think they’ll over- or under-cook it. But it’s just as easy to cook as any other fish! And when it’s still a little pink in the middle, it’s unbelievably tender, not at all fishy, and meaty like a steak.
Table of Contents
These juicy tuna steaks are coated in my copycat Prudhomme’s seafood seasoning made from Cajun spices that are perfect for seafood: paprika, cayenne, black pepper, ground ginger and clove, oregano, and a few others. It’s a little spicy, smoky, very earthy, and entirely delicious!
(Be sure to check the recipe card for a full list of ingredients and quantities)
- Ahi Tuna – Choose a firm, red steak that’s uniform in color. It shouldn’t be mushy or smell fishy.
- Melted Butter – To substitute the butter in this blackened ahi tuna recipe, use a high smoke point oil like avocado or canola.
- Cajun Blackening Seasoning – Again, I usually use my Cajun seafood seasoning blend, but if you don’t have any premade on hand use the following:
- Paprika – Sweet paprika is my preference for seafood. It’s fruity and tangy but still a little smoky.
- Cayenne Pepper – Spicy cayenne pepper introduces that characteristic Cajun kick. If you’re worried about the level of heat, start with ¼ teaspoon and see how you like it.
- Ground Ginger & Cloves – These seasonings add a different kind of “spice” to the blend: warm, earthy, and a little bitter. The best substitutes for ground clove or ginger in this blackened ahi tuna recipe would be mace or cardamom.
- Black Pepper – Not too intimidating, right? Black pepper adds a familiar heat that isn’t as abrasive as cayenne.
- Dried Oregano – For a subtler flavor, use marjoram — it’s like oregano’s mild, sweet sibling.
- Fennel Seeds – I know not everyone likes fennel! If it isn’t for you, substitute with anise, cumin, dill, or parsley if you want an “herbal” flavor.
- Salt – Just ½ teaspoon will enhance the flavor of the tuna tenfold.
- Rinse & Slice the Fish. Rinse the fish under cold, running water to eliminate some of the “fishiness.” Pat dry and slice into four ½ inch steaks.
- Make the Blackening Seasoning. Add all of the Cajun blackening spices to a small bowl and whisk together. Set aside.
- Preheat the Skillet. Preheat a cast iron skillet on high heat until it starts smoking. Keep the area well-ventilated — crack the windows, turn on the stove fan or ceiling fan, etc.
- Coat the Fish. Dip the tuna steaks in the melted butter and then coat them in the blackening seasoning, pressing the spices onto the fish to help them stick.
- Sear. Transfer the seasoned fish to the hot skillet and sear for just 10 seconds on each side (or up to 30 seconds per side for well-done).
- Serve your blackened ahi tuna right away with a squeeze of fresh lemon and any preferred sides like barley salad, mango pico de gallo, or roasted vegetables.
Recommended Tools
- Cast Iron Skillet – There’s no beating a seasoned skillet for quick searing. A regular frying pan is fine, but it should be a good quality, nonstick pan.
Storing and Reheating
Leftovers are best eaten within 1 or 2 days. This dish, as with most seared fish, is most delicious and has the best texture right off the stovetop.
Reheat blackened ahi tuna the same way you made it —with a quick sear on the stovetop! Preheat the skillet on medium-high heat and warm for about 30 seconds per side.
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It largely depends on your preference! Ahi tuna is often enjoyed rare or medium-rare. It can even be eaten raw!
In the interest of this blackened ahi tuna recipe, I would say the fish is “done” when a sear is achieved on each side of the steak. The center will be pink, or medium-rare. Medium ahi tuna will be slightly pink (20 seconds per side) and well-done will have no pink (30 seconds per side).
Raw ahi tuna should be deep, glossy red, and translucent.
With two super easy steps: keep the fish chilled and coat it in butter. That’s it!
These two steps work together. Melted butter will adhere better to cold fish, solidifying slightly when it comes in contact. The seasoning, in turn, clings to the melted butter and coats the fish.
It’s spicy in the way all Cajun food is. The seasoning in my blackened ahi tuna recipe contains cayenne, paprika, and black pepper.
The heat can be managed by simply using less of these spices (cayenne is the spiciest) when mixing the spice blend.
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Blackened Ahi Tuna
- 1 lb fresh ahi tuna
- 1/4 cup melted butter
Cajun Blackening Seasoning
- 1 tsp paprika
- 1/2 tsp salt
- 1/2 tsp cayenne pepper
- 1/4 tsp ground ginger
- 1/4 tsp black pepper
- 1/4 tsp oregano
- 1/4 tsp fennel seeds
- 1/8 tsp ground clove
- Rinse the fish and pat dry with paper towels. Slice into 1/2 inch steaks.
- 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 ahi tuna in melted butter and then coat with spice mixture on both sides. Press spice mixture to adhere. Immediately sear on high heat each side for 10 seconds for pink in the middle, or for no more then 30 seconds per side to cook through well. Serve immediately.
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.
I have made this numerous times. I use my griddle on my gas grill and then no smoke inside! It is absolutely delicious. Pair it with Arugula and Tomatoes from my garden with some Garbanzo beans and a drizzle of olive oil and balsamic vinegar. Best dinner!
Sounds perfect!
I usually sear ALL sides of ahi and then put in refrigerator for at least 4 hrs. Then slice and serve with shoyu and wasabi
Seared ahi is just THE best, right?! So good. 🙂
So good! I made them bite size and will definitely use this recipe again!
One of my all-time favorites, too! Thanks for coming back to let me know Anne.
Hi Kevin,
I made this last night and it was out of this world!! At first I thought using fennel was kinda weird…thinking that it’s mostly in sausage, but WOW! I’m so glad I did it your way! The Hubby loved it too! Thanks for all you do, I love your site and refer to it often.
This turned out so freakin good!! A lot of smoke, but worth it! Didn’t have fennel, but still turned out very well. Will be making this regularly!
Thanks Tawni, one of my smoky favorites too!
You may be burning butter if too hot. Maybe use Avacodo oil as it has a high heat stamina and use melted butter after you cook the dish.
I give it a try and see, thanks Rich!
Thanks Kevin,,, Great Recipe😀
Thank you so much!
Thank you for the excellent recipe. I’ve made it three different times using a cast iron skillet – twice with tuna and once with salmon. The flavors if the rub tasted great with both types of fish. I altered the recipe slightly by cutting the regular paprika back to 1 half tsp. and adding 1 half tsp. of smoked paprika. It’s so good, it was worth having to open the windows even in cold weather to ventilate the kitchen to keep my smoke alarms from going off.
Thanks for taking the time to come back and let me know Joan. 🙂
thank you for this recipe!! Cut the tuna into bite size pieces, tossed with EVOO and your awesome recipe for the rub. Placed on a grill mat and it was deeelish!!! Keep em comin’!!!
Spices were perfectly aligned to bring out the flavor of the tuna!
That is a great idea cutting them into bite size pieces! I am glad you enjoyed them!