Blackened swordfish makes a quick, flavorful dinner in less than 20 minutes! Swordfish steaks are pan seared in a skillet, then finished in the oven and topped with Cajun butter.
Why You'll Love it:
Swordfish is a versatile, mild tasting fish that's easy to make and super quick!
It's best when it's jazzed up with strong flavors like this blackened swordfish or my oven baked swordfish with lemon basil butter!
You can grill, bake, or pan-sear it. For this blackened swordfish recipe, I pan-sear it, then finish it in the oven. The sizzling hot skillet creates a crispy top that melts the flavored butter for a juicy bite!
This recipe serves two, but you could easily double it and make it for four people!
Swordfish - You can use swordfish steaks or select cuts, fresh or frozen. Just be sure to thaw frozen steaks before you plan to use them. The thinner the steaks, the quicker they cook! Keep this in mind so you don't overcook them.
Olive oil - For the skillet! Olive oil encourages golden brown caramelization and a crispy exterior, plus it adds flavor!
Spices - I used paprika, salt, pepper, cayenne, oregano, onion powder, and garlic powder. If you want to use a Cajun spice mix, that works great too.
Butter - For the Cajun butter. It only takes a minute and melts directly on top of the swordfish!
Lemon - To brighten up all the bold flavors! Go for a real lemon, not the bottled juice.
How to Thaw Frozen Swordfish:
Never thaw frozen swordfish in hot water! Not only will it partially cook the fish and create a rubbery texture, but it's not safe bacteria-wise.
Here's a couple of ways you can properly thaw swordfish:
- In the fridge - The night before you plan to make blackened swordfish, place the steaks in the fridge to thaw. I prefer this method because it only takes 2 seconds and a bit of forethought.
- In cold water - Fill a large bowl with cold water and place the vacuum sealed steaks inside to thaw. They should thaw in 30 minutes or so. If your steaks aren't vacuum sealed, place them in a sealed bag first.
How to Make Blackened Swordfish:
My method for blackened swordfish is quick and simple. It goes as follows - season, pan-sear, bake.
Before you start, preheat your oven to 350 degrees and heat a 12-inch skillet over medium-high heat.
Dry swordfish - Use a paper towel to dry the outside of the steaks. Excess moisture creates steam, preventing a deep, golden brown sear.
Season - In a small bowl, mix all the spices together. Use a ¼ teaspoon to generously season the top side of each steak.
Pan-sear - Add the olive oil to the hot skillet. Carefully place each swordfish steak, seasoned side down, into the hot skillet. Let them sear for 5 minutes without fiddling with them!
Bake - Use a thin-set spatula to turn each steak over. The top should be caramelized. Place the entire skillet, steaks and all, into the oven. Bake for 8 to 10 minutes. It largely depends on the thickness of your swordfish.
Make compound butter - In a medium bowl, combine the softened butter, remaining spices, lemon zest, and juice. Mash well with a fork.
Serve - Use an oven mitt to remove the hot skillet from the oven. Carefully transfer the swordfish to plates and top each one with two teaspoons of Cajun butter. Enjoy immediately!
- Leave the swordfish alone in the skillet. The longer it sits directly in contact with the hot skillet, the better the sear. If you move it, it won't caramelize effectively.
- Don't overbake the fish. Overbaked swordfish tastes dry and tough! The thinner the steaks, the quicker they cook. Start with 8 minutes in the oven, then add more time if needed. Swordfish is done when it flakes easily. The internal temp should be around 130 degrees for medium.
- Don't touch the skillet handle with your bare hands! The handle will be very hot! It's easy to forget it was in the oven. Leave an oven mitt on the handle so you don't accidentally grab it.
- Thaw frozen swordfish before you cook it. Frozen swordfish won't sear properly and may not cook evenly.
- Dairy-free - Swap the butter with a dairy-free substitute. The options are endless.
- Cajun seasoning - If you want to, you can swap all the spices with 1 ¼ teaspoons of Cajun seasoning.
- Skillet - I used a nonstick skillet, but a cast iron skillet works great too!
What is the dark spot on a swordfish steak?
The dark red area doesn't mean your swordfish is bad! It's a muscle that's high in myoglobin, a blood pigment. It's safe to eat. It has a slightly stronger flavor than the lighter areas though. If you want to avoid it, buy swordfish cuts instead of steaks.
Blackened Swordfish with Cajun Butter
- 12-inch oven-safe skillet
- 2 swordfish steaks or select cuts
- 2 tablespoons olive oil
- ¼ teaspoon paprika
- ¼ teaspoon kosher salt
- ¼ teaspoon onion powder
- ¼ teaspoon garlic powder
- ⅛ teaspoon black pepper
- ⅛ teaspoon cayenne pepper
- ⅛ teaspoon oregano
- 2 tablespoons unsalted butter softened
- ½ lemon, zested
- 1 teaspoon lemon juice
- Preheat oven to 350 degrees Fahrenheit.
- Heat a 12-inch nonstick or cast iron skillet over medium-high heat.
- While the pan heats up, make the spice mixture. In a small bowl, combine the paprika, salt, pepper, cayenne, oregano, onion powder, and garlic powder. Mix with a spoon.
- Dry the swordfish steaks with a paper towel, then sprinkle ¼ teaspoon of the spice mixture on top of each steak, coating the entire surface.
- Add the olive oil to the hot skillet. Carefully place the steaks into the skillet, seasoned side down.
- Let the steaks sear for 5 minutes. Do not move them.
- Use a thin-set spatula to carefully turn the steaks over. Immediately place the skillet into the oven and bake for 8 to 10 minutes. When it's opaque and flakes easily, it's done!
- While the swordfish cooks, make the Cajun butter. In a small bowl, mash the butter with the remaining spice mixture, lemon zest, and juice.
- Use an oven mitt to carefully remove the hot pan from the oven. Do not touch the handle with your bare hands!
- Use a thin set spatula to transfer the swordfish steaks to serving plates. Top each steak with two teaspoons of Cajun butter. Enjoy!