Name: Blackened Mahi Mahi Recipe
Prep time: 5 min
Cook time: 10 min
Total time: 15 min
Ingredients: 4 mahi mahi fillets (4-6 ounce portions); 1 tsp sea salt; 1 tsp chili powder; 1 tsp ground cumin; 1 tsp garlic powder; 1 tsp onion powder; 1/2 tsp smoked paprika; 1/2 tsp black pepper; 1/4 tsp cayenne pepper; 1/4 tsp dried thyme; 2 tbsp butter or extra virgin olive oil; 1 lime

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This easy recipe for Blackened Mahi Mahi comes together in just 15 minutes – making it the perfect weeknight dinner idea! Crusted with spicy blackened seasonings and baked in the oven on a sheet pan, it’s both healthy and satisfying. Serve it with white rice and delicious mango salsa, or on top of your favorite salad.

There’s one thing that my elders instilled in me from an early age – never, ever skimp on seasonings, not even on a school night! This recipe for Blackened Mahi Mahi clearly speaks to the island-girl and believe it or not, the busy mom in me.

I’ve been making my own blackened spice for years. I prefer to make my own spice blend because it takes just a few seconds to combine and I get to control the level of spice for the little ones. Feel free to adjust the recipe to suit your own taste!

Why you’ll love this recipe:

It’s quick and easy – there’s just a few simple steps and and you’ll be done in 15 minutes, flat, I’m not exaggerating.
Adjust the seasoning to your liking – most of the heat is in this recipe comes from cayenne and black pepper which can be modified. Chili powder and paprika also have varying degrees of spiciness, so feel free to play around with varying amounts of spices. Avoid adding more salt if you can.
Can be served different ways – serving suggestions are further down in the post, but you can use blackened mahi mahi to make tacos, as a protein with salad or in a sandwich.
There’s very little clean up since we’re using a sheet pan. Line your sheet pan with parchment paper to protect from burn marks and staining. It’s always good to give your sheet pan a quick rinse with soapy water but you won’t have to scrub any pans or clean an air-fryer.

What does the term “blackened” mean?

Blackening is a way of seasoning protein, giving it a spicy flavor and dark color. Much like Cajun seasoning, blackened spice is made from a mixture of chili powder, seasonings and dried herbs, adding both taste and visual appeal. It’s commonly used to season fish, shrimp and chicken and is popular in Southern cooking.

Blackening reminds me of a similar approach called “jerk”, that’s popular in West Indian cultures. Jerk also involves a mix of spices, but uses allspice and Scotch bonnet peppers resulting in a darker color, spicier flavor, and a distinctly different taste from blackened food. It’s applied in a similar way, but usually marinated for longer and often used for chicken and pork dishes.

Ingredients you’ll need

Mahi mahi is a mild tasting, salt water fish that has a moist and flaky texture when it’s prepared correctly. Fresh or frozen both work great for this recipe.
Blackened seasoning – spices can vary, but I use cayenne pepper, chili powder, ground paprika, onion powder, garlic powder, cumin, fresh thyme, sea salt and pepper.
Olive oil or melted butter – brushing the fish with some type of fat adds flavor and seals in moisture as it finishes cooking.
Fresh lime – adding a drizzle of lime right at the enhances the flavor of the fish and spices. Keep a few lime wedges aside for garnishing.

Tips for choosing the best mahi mahi

As with any type of seafood, mahi mahi should be bought from a reputable source. Here are some tips for buying it fresh or frozen:

Mahi mahi should have a pale pink color as pictured above. If you see any spots or odd colors, it’s best to avoid it as it might not be fresh.
Frozen mahi mahi should be vacuum-sealed. Make sure to check the printed date on the outside on the package before buying.
Fish should smell fresh and have a firm texture. Toss it if it feels mushy, slimy, sticky, or if it has an unpleasant smell.

Recipe substitutions

Some great alternatives to mahi mahi are cod, haddock or scrod as they’re all mild in taste and have similar cooking times. Salmon is another excellent choice, but may take an extra 2-3 minutes to cook.
Adjust the intensity of the spices by reducing the amount of salt or cayenne pepper. For stronger/spicier flavor, use chipotle powder instead of regular chili powder.
Substitute sea salt for kosher or Himalayan salt, basically use what you have!
Brush the fish with melted butter instead of olive oil for even more rich flavor.
If you don’t have fresh limes on hand, use lemons instead.

How to make Blackened Mahi Mahi

This recipe involves just a few simple steps. You’ll need just a sheet pan and a metal fish spatula.

Prepare the seasoning mixture by combining the salt and dry spices in a bowl and setting them aside.
Preheat your oven to 400°F. Pat each of the mahi mahi steaks dry using paper towels.
Season the mahi mahi by sprinkling a generous amount of the seasoning mixture over each steak. As you’re coating the fish, press down gently to make sure the seasonings stick and shake off any excess.
Place the mahi mahi on a baking sheet lined with parchment paper and bake for 10 minutes. When there are 2 minutes left (around the 8-minute mark), softly brush the top of each steak with olive oil or melted butter. Close the oven and continue to bake for the remaining 2 minutes.

Tips and Other Cooking Methods

Thawing directions – place the frozen mahi steaks in a bowl and thaw them overnight in the refrigerator. Thawed fish retains water, so you’ll need to firmly pat it dry using paper towels to squeeze out any water.
As a rule of thumb, bake mahi mahi for about 10 minutes for every 1 inch of thickness. In this recipe, I use 1-inch thick mahi mahi steaks and bake them for exactly 10 minutes.
Instead of baking, pan sear the mahi mahi in a large skillet with 2 tablespoons of melted butter for 3-4 minutes on each side. You’ll need a metal fish spatula to flip the delicate fish. Since the skillet is directly over the flame, the fish doesn’t need to cook as long as it would if you were baking it in the oven.
To baste the mahi mahi, cook it in a skillet without flipping it over. Use a spoon to drizzle the melted butter over the fish as it cooks. Repeat this basting process for 7-8 minutes, making sure the mahi mahi is evenly coated. You’ll need about 3-4 tablespoons of butter for basting.

Sides and Serving Suggestions

My favorite way to enjoy blackened mahi mahi is on a bed of white rice with cooling mango salsa on the side. You can also try it:

As a fish sandwich – on a brioche bun or french roll – with lettuce and tomato or tangy coleslaw.
With a bed of mixed greens or on top of a Caesar salad.
In fish tacos with flour tortillas and fresh cabbage.

Storage tips

In the refrigerator: wrap the leftover mahi in plastic wrap and store in an airtight container for up to 3 days.
In the freezer: place the wrapped mahi mahi in a freezer bag where it can be stored for for up to 3 months. Thaw it overnight in the refrigerator when you’re ready to enjoy it again.
Re-heat leftovers in a 350°oven for 7-10 minutes, or microwave for 45 seconds.

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Blackened Mahi Mahi Recipe