Cajun Fish Recipe

If you love bold, fiery flavours and quick weeknight meals, Cajun fish might just become your new favourite recipe. It’s fast, simple and absolutely bursting with flavour. In the US South, where this dish comes from, blackening is more than just a cooking technique – it’s a tradition. Once you learn the method, you’ll use it again and again, not just for fish but for chicken, prawns, and even veg.

Today we’re diving deep into everything you need to know to make perfect Cajun blackened fish at home. I’m talking proper seasoning, proper sear, proper flavour… all without setting off the smoke alarm (hopefully!).

Let’s fire up that pan.

Cajun Fish on a serving plate with fried rice.

What is Cajun Blackened Fish?

“Blackening” is a cooking technique where fish, chicken or meat is coated in melted butter, dipped in a spicy Cajun blend and then seared in a ripping-hot cast-iron pan until charred. It looks burnt, but it’s not. The black crust is the butter and spices caramelising. Inside, the fish stays flaky, juicy and absolutely packed with flavour.

Cajun fish is:

Spicy
Smoky
Buttery
Crispy on the outside
Tender inside
Full of deep Louisiana flavour

If you’ve ever wanted a dish that looks restaurant-level but takes 15 minutes from start to finish, this is the one.

A Brief History of Blackened Cajun Fish

Though blackened dishes feel like old Cajun tradition, the style as we know it today was made famous in the 1980s by legendary Louisiana chef Paul Prudhomme. Prudhomme wasn’t trying to create a culinary trend. He simply dunked redfish in butter, coated it in spices, blasted it in a blazing cast-iron skillet and people went mad for it.

Restaurants across America started serving “blackened” everything, fish, chicken, steak, even blackened tofu and veg.

But the roots go deeper. Cajun cuisine itself was created by the Acadian French who were exiled from Canada and settled in Louisiana. They adapted their French cooking to new ingredients – spices, peppers, local fish, Southern produce – creating one of the most flavourful food cultures on the planet.

Ingredients

There aren’t a lot of ingredients in this one. I highly recommend trying my homemade Cajun seasoning recipe. You will find exact ingredient measurements in the printable recipe card at the bottom of this page.

See recipe card for quantities.

Fish fillets or whole fish
Butter
Cajun seasoning
Lemon
Parsley or spring onions

Step by step photos

Check out my step by step photos to see just how easy it is to make Cajun fish at home. You will find the ingredient measurements in the printable recipe card at the bottom of this page.

Scraping excess moisture from the skin of the fish.

Step 1: If using whole skin-on fish, scrape the skin with a knife to get as much moisture out of the skin as you can. It should feel paper dry. This will get you a crispier, not soggy, skin.

Step 2: Melt the butter in a pan. The butter will be used to cook the fish and also help the Cajun seasoning adhere to the fish.

Step 3: Dip each fillet or whole fish fully into the butter. If cooking whole fish, I recommend scoring the fish on both sides a few times.

The fish coated with Cajun seasoning before cooking.

Step 4: Pour the Cajun seasoning onto a plate or other clean surface. Then press the fish into the Cajun seasoning until it’s generously coated on both sides. Don’t hold back! This dish is meant to be heavily spiced.

Adding the fish to the hot butter in the sizzling hot pan.

Step 5: Over a high heat, place your fillets or whole fish in the butter in the pan. They should sizzle loudly on contact.

Step 6: Cook fillets for 2–3 minutes per side or about 5 to 8 minutes per side for whole fish. The spices will turn deep brown to black. This is exactly what you want. The fish is cooked when the flesh is white and not opaque.

Basting the fish with the butter in the pan.

Step 7: Be sure to baste the fish with the melted butter a few times during the cook. Believe me… it makes all the difference.

The Cajun fish on a serving plate with fried rice.

Step 8: Squeeze lemon on top, garnish with herbs and serve immediately while the crust is crisp.

Variations You’ll Love:

Blackened fish is only the beginning. Try these:

1. Blackened Chicken: Use chicken breast or thighs and cook in the same way. Absolutely delicious in sandwiches and tacos.

2. Blackened Prawns: Perfect for toss-through pasta or salads.

3. Blackened Salmon: Rich, fatty salmon stands up perfectly to the spice crust.

4. Blackened Fish Tacos: Top with slaw, lime, jalapeños, and chipotle mayo.

5. Blackened Veg: Cauliflower steaks, mushrooms, or aubergine all take beautifully to this technique.

Useful Equipment

You don’t need a restaurant kitchen, but a few key tools make a huge difference:

1. Cast-Iron Skillet or another heavy pan: To form a delicious crust, you need a good pan that can cook evenly at a high heat.

2. Fish Spatula: Thin and flexible, ideal for flipping delicate fillets.

3. Mixing Bowl: For combining your Cajun seasoning.

4. Kitchen Tongs: Helpful when handling hot fish fillets.

5. Oven Vent or Open Window: This dish gets smoky. Trust me… ventilation helps.

Storage and Reheating

Blackened Cajun fish is best eaten fresh but here’s how to store leftovers:

Storing

Cool completely
Place in an airtight container
Refrigerate for up to 2 days

Freezing

You can freeze it, but the crust softens slightly. Freeze for up to 2 months.

Reheating

Oven: 180°C for 8–10 minutes
Air fryer: 3–4 minutes
Pan: Gently warm in a non-stick pan with a tiny bit of oil

Avoid microwaving unless you don’t mind soft fish and a very intense Cajun aroma!

Top Tip

Don’t move the fish too early. Let it sit for a solid 2 minutes to form a crust before flipping.

FAQ

Is blackened fish burnt?

No! It looks black but it’s the spices caramelising and toasting. The flavour is smoky, not bitter.

Is Cajun seasoning the same as Creole seasoning.

Can you use vegetable oil instead of butter?

You can, but butter caramelises better and gives that iconic crust.

Can you bake or grill the fish instead of frying?

Yes! It won’t get quite the same crust, but it works. You can bake it in your oven at 220°C for 10 to 12 minutes or grill/BBQ for 2 to 3 minutes per side.

Looking for other recipes like this? Try these:

Pairing

A good side of rice always goes down well.

Have you tried this Blackened Cajun Fish recipe?

If yes, please give it a star rating in the recipe card below and leave a comment. I love receiving your feedback and I’m sure other readers of my blog do too. Thank you.

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Yield: 4

Cajun Fish

Prep Time
5 minutes

Cook Time
15 minutes

Total Time
20 minutes

Ingredients

4 fish fillets or 2 whole fish (Bream, bass, catfish, cod, haddock, tilapia, salmon, or redfish)
6 tbsp melted butter
7 tbsp Cajun seasoning
Lemon wedges, to serve
Fresh parsley or spring onions, for garnish

Instructions

If using whole skin-on fish, scrape the skin with a knife to get as much moisture out of the skin as you can. It should feel paper dry. This will get you a crispier, not soggy, skin.
Melt the butter in a pan. Then dip the fish into the melted butter so the spices stick and most importantly, to help build that blackened crust.
Place it over high heat for 5–8 minutes. You want it blazing hot, almost smoking.
Dip each fillet fully into the butter. Then press it into the Cajun seasoning until it’s generously coated on both sides. Don’t hold back! This dish is meant to be heavily spiced.
Add a teaspoon of butter or oil to the hot skillet and immediately place your fillets or whole fish in the pan. They should sizzle loudly. Cook fillets for 2–3 minutes per side or about 4 minutes per side for whole fish. The spices will turn deep brown to black. This is exactly what you want.
Squeeze lemon on top, garnish with herbs and serve immediately while the crust is crisp.