This Blackened Mahi Mahi recipe brings bold Cajun flavor to your kitchen with a simple spice blend and quick stovetop sear. Tender, flaky fish develops a deeply seasoned crust while staying moist inside, pairing perfectly with homemade mashed potatoes or steamed cilantro lime rice.
Why You'll Love This Blackened Mahi Mahi Recipe
Blackened mahi mahi screams "wow" without breaking a sweat. You will love how fast this comes together with simple spices you probably already have on hand and an easy stovetop cook. The bold crust and tender flaky fish make it feel like a restaurant style dinner without any extra fuss. Even seafood skeptics will be won over by its bold, enticing flavors.
- Fast & Easy: Cooks up in a flash, making it a weeknight win - hello, quick and delicious!
- Spicy Cajun Flavors: A fiery Cajun blackening crust on the sweet mahi, creates extra flavor.
- Versatility Champion: Pair it with rice, veggies, tacos, salads - the possibilities are endless!
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Ingredients Overview
You can use fresh or frozen mahi mahi fillets when making this recipe for a firm but flaky fish that cooked equally as well baked, broiled, or grilled.
- Mahi Mahi filets - Look for uniform size mahi fillets, about 6 oz each.
- Cajun or Creole seasoning blend - Try our Homemade Blackening Seasoning, or your favorite store bought brand. Tony Chachere and Zatarains's Blackening seasoning are other good choices, as well as our recipe for Blackening Seasoning.
- Olive oil - To lightly brush on the raw mahi fillets.
- Lemon - Cut in wedges to serve as garnish.
- Tartar Sauce - Optional, try our homemade Tartar Sauce.
Full ingredient amounts and preparation instructions are in the printable recipe card at the bottom of this post.
What Is Mahi Mahi?
Mahi mahi is a firm, mild white fish known for its slightly sweet flavor and meaty texture. It holds up well to grilling, searing, and bold seasonings, which makes it a popular choice for dishes like tacos, sandwiches, and blackened fish recipes.
Despite its name, mahi mahi is not related to dolphin and is actually a fast-growing ocean fish often called dolphinfish.
How To Make Blackened Mahi Mahi
Making this recipe starts with preparing a simple spice blend and coating the mahi mahi fillets in melted butter and seasoning. The fish is then cooked in a hot skillet until a dark crust forms while the inside stays tender and flaky.
Follow the step-by-step visual guide below to see each stage from prep to plating.
- Prepare the Louisiana Cajun Seasoning and set it aside in a small bowl.
- Pat mahi fillets dry with paper towels.
- Lightly brush both sides of each fillet with melted butter.
- Coat the mahi mahi filets generously with the blackening seasoning, pressing it in so that it sticks to the fish on both sides.
- Place a 12 inch cast iron skillet over medium-high heat until very hot (almost smoking). Add fillets and cook about 3-4 minutes per side, until a dark crust forms and fish flakes easily.
Serving Suggestions
Serve blackened mahi mahi with simple sides that complement its smoky spice and flaky texture. A scoop of Cajun butter corn adds a touch of sweetness and warmth, while a creamy coleslaw provides cool crunch that balances the seasoning.
For a heartier plate, pair the fish with crispy air fryer potatoes or tuck slices into warm tortillas with fresh toppings for easy fish tacos.
Substitutions and Variations
Blackened Mahi Mahi is a perfect fish to bake or broil with blackening seasoning. Some useful tips and substitutions when making this recipe:
- Swap the fish: Use cod, halibut, snapper, or tilapia if mahi mahi is unavailable since other firm white fish hold up well to blackening seasoning and high heat.
- Adjust the heat level: Reduce or omit cayenne for a milder flavor or add extra cayenne or chipotle powder if you enjoy more spice.
- Use store bought seasoning: Replace the homemade spice mix with your favorite Cajun or blackened seasoning blend to save prep time.
- Try grilling instead: Cook the seasoned fillets on a hot grill for a lightly smoky flavor and similar charred crust.
- Make it dairy free: Swap melted butter for olive oil or avocado oil while still helping the seasoning adhere and brown nicely.
- Add citrus variation: Use lime instead of lemon for a brighter finish that pairs well with taco style serving.
- Turn it into tacos: Flake the cooked fish and serve in tortillas with slaw and avocado crema for a casual meal variation.
Tips for Success
Helpful tips to help you when making this recipe:
- Pat the fish dry: Removing excess moisture helps the butter and seasoning stick better and encourages a proper crust to form.
- Preheat the skillet well: A very hot pan is essential for creating the signature blackened exterior without overcooking the fish.
- Avoid overcrowding: Use a large 12 inch skillet to sear all 4 filets at the same time, or cook in batches if needed. This keeps the pan hot and prevents steaming instead of searing.
- Resist flipping too soon: Let the fillets cook undisturbed so the spice coating sets and releases easily from the pan.
- Check for doneness: Cook just until the fish flakes easily with a fork to keep the texture moist and tender.
Storage Options
Here is how I store leftovers when making this recipe:
- Refrigerate leftovers: Store cooled fillets in an airtight container in the refrigerator for up to 3 days to maintain quality and food safety.
- Freeze for longer storage: Wrap individual portions tightly and freeze for up to 2 months so you can reheat only what you need.
- Use shallow containers: Keeping fish in a shallow sealed container helps it chill quickly and prevents excess moisture buildup.
- Reheat gently: Warm leftovers in a skillet over low heat or in the microwave at reduced power to avoid drying out the fish.
- Repurpose leftovers: Flake chilled fish into salads, wraps, or tacos for an easy second meal without additional cooking.
Related Recipes
- Cajun Shrimp and Grits
- Louisiana Cajun Seasoning
- Old Fashioned Buttermilk Biscuits
- Easy Cajun Cornbread
- Mardi Gras King Cake
Frequently Asked Questions
Blackened mahi mahi refers to fish coated in a Cajun style spice blend and cooked over high heat so the seasoning forms a dark, flavorful crust.
Yes, mahi mahi is ideal because its firm texture holds together during high heat cooking and supports bold seasoning without falling apart.
A cast iron skillet works best because it retains heat well, but any heavy skillet that can get very hot will also work.
This usually happens if the pan is not hot enough or if the fish was too wet before seasoning, which prevents proper searing.
Mahi mahi is done when it turns opaque and flakes easily with a fork while still remaining moist inside, usually about 3-4 minutes per side.
Yes, grilling works well and adds a light smoky flavor while still allowing the spice crust to develop.
Yes, frozen fillets work well as long as they are fully thawed and patted dry before seasoning and cooking.
Yes, the spice blend can be mixed in advance and stored in an airtight container for several months for quick use later. It's great on shrimp and steaks as well.
Mardi Gras Recipes
Get The Recipe!
Blackened Mahi Mahi
Equipment
- 12 inch cast iron skillet
Ingredients
For the Mahi Mahi
- 4 mahi mahi fillets 4-6 oz each, thawed if frozen
- 2 tablespoons butter melted
- Lemon wedges for garnish
- tartar sauce optional
Blackening Seasoning
- 1 teaspoon smoked paprika
- 1 teaspoon garlic powder
- 1 teaspoon onion powder
- 1 teaspoon dried thyme
- 1 teaspoon dried oregano
- ½ teaspoon cayenne adjust heat level
- 1 teaspoon kosher salt
- ½ teaspoon black pepper
Instructions
Make the Blackening seasoning:
- Mix all blackening spices in a small bowl.1 teaspoon smoked paprika, 1 teaspoon garlic powder, 1 teaspoon dried thyme, 1 teaspoon dried oregano, ½ teaspoon cayenne, 1 teaspoon kosher salt, ½ teaspoon black pepper, 1 teaspoon onion powder
Prepare the Mahi Mahi
- Pat mahi mahi dry with paper towels (this helps the crust form).4 mahi mahi fillets
- Brush both sides with melted butter, then coat generously with seasoning, pressing it in so that it sticks to the fish on both sides.2 tablespoons butter
- Place a cast iron skillet over medium-high heat until very hot (almost smoking).
- Add fillets and cook about 3-4 minutes per side, until a dark crust forms and fish flakes easily.
- Finish with lemon squeeze and extra butter drizzle if desired.Lemon wedges, tartar sauce
Notes
- Pat the fish dry: Removing excess moisture helps the butter and seasoning stick better and encourages a proper crust to form.
- Preheat the skillet well: A very hot pan is essential for creating the signature blackened exterior without overcooking the fish.
- Avoid overcrowding: Use a large 12 inch skillet to sear all 4 filets at the same time, or cook in batches if needed. This keeps the pan hot and prevents steaming instead of searing.
- Resist flipping too soon: Let the fillets cook undisturbed so the spice coating sets and releases easily from the pan.
- Check for doneness: Cook just until the fish flakes easily with a fork to keep the texture moist and tender.
Nutrition
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Kelly Bloom says
My family loved this!