Blackened grilled swordfish pairs thick, meaty steaks with a bold paprika-and-herb crust and the smoky flavor of a hot grill. A little oil helps the seasoning cling, while quick cooking keeps the fish moist and lets the spices toast without burning.
Ingredients
- 4 swordfish steaks, about 6 ounces (170 g) each and 1 inch thick
- 1 tablespoon olive oil, plus a little more for the grill grates
- 1 tablespoon sweet paprika
- 1 teaspoon dried thyme
- 1 teaspoon dried oregano
- 1 teaspoon garlic powder
- 1 teaspoon onion powder
- 3/4 teaspoon kosher salt
- 1/2 teaspoon freshly ground black pepper
- 1/4 teaspoon cayenne pepper, or less to taste
- 1 lemon, cut into wedges, for serving
Instructions
- Prepare the fish. Pat the swordfish steaks dry with paper towels. Check for any small bones and remove them with clean tweezers. Let the fish sit at room temperature for 10 to 15 minutes while you prepare the grill; do not leave it out for more than two hours, or one hour if the room is above 90°F (32°C).
- Mix the seasoning. In a small bowl, stir together the paprika, thyme, oregano, garlic powder, onion powder, salt, black pepper, and cayenne. Brush both sides of each steak lightly with olive oil, then press the spice mixture evenly over the surfaces and edges. Use all the mixture, dividing it between the steaks.
- Heat the grill. Preheat a gas grill to medium-high, about 400 to 450°F (204 to 232°C), or prepare a charcoal grill for a hot, direct-heat zone. Clean the grates and lightly oil them with an oiled paper towel held with tongs. The grill should be hot enough to sear the fish, but avoid flames or flare-ups that can scorch the spices.
- Grill the first side. Place the steaks over direct heat and close the lid. Cook for about 4 minutes without moving them, until the underside has browned grill marks and the fish releases fairly easily when nudged with a thin spatula. If a steak sticks, give it another 30 seconds rather than pulling it up by force.
- Turn and finish. Flip carefully and grill for another 3 to 5 minutes, depending on thickness and grill heat. Start checking the center early with an instant-read thermometer inserted from the side into the thickest part. For food safety, cook swordfish to 145°F (63°C); the center should be opaque and separate easily into firm flakes. If it is not there yet, cook in 1-minute intervals and check again.
- Rest and serve. Transfer the steaks to a clean plate and rest for 3 minutes. Serve with lemon wedges. Discard any spice mixture or marinade that touched raw fish, and use clean utensils and plates for the cooked steaks.
Tips
- Choose steaks of even thickness. Pieces close to 1 inch thick cook at a similar rate. If yours are thinner, check them sooner; thick steaks may need a few extra minutes. A thermometer is more dependable than timing alone.
- Keep the seasoning from scorching. Paprika and dried herbs can turn bitter over open flames. Use a clean, hot grill with controlled heat, keep the lid closed between checks, and move the fish to a cooler part of the grill if flare-ups begin.
- Adjust the heat to suit your table. The 1/4 teaspoon cayenne gives a gentle kick. Omit it for a mild crust or increase it slightly if you enjoy more heat. Smoked paprika can replace sweet paprika for a more pronounced smoky taste.
- Use a thin, wide spatula. Swordfish is sturdy but can still split when turned roughly. Slide the spatula fully beneath each steak and flip once, after the first side has seared.
Serving Suggestions
Squeeze fresh lemon over the fish just before eating to balance the rich, savory crust. Serve it with grilled vegetables such as zucchini, asparagus, or bell peppers, or pair it with corn on the cob and a simple green salad. Rice, couscous, or roasted potatoes make the meal more filling and catch the lemony juices. A cool cucumber-yogurt sauce or a spoonful of fresh tomato salsa also works well alongside the spices.
Variations
For a less spicy version, leave out the cayenne and add an extra 1/4 teaspoon paprika. For a deeper, woodsy flavor, use smoked paprika, while keeping the grill temperature controlled so the seasoning does not burn. You can substitute swordfish with similarly thick tuna steaks, mahi-mahi, or salmon; the cooking time will vary, so check the thickest part with a thermometer and follow safe temperature guidance for the fish you choose. For a brighter herb profile, add 1/2 teaspoon finely grated lemon zest to the spice mixture. Avoid adding fresh minced garlic to the outside before grilling, since it can burn quickly.
Storage and Reheating
Refrigerate leftover swordfish within two hours of cooking (within one hour when the air temperature is above 90°F/32°C). Store it in an airtight container at 40°F (4°C) or colder and eat within 3 to 4 days. For best quality, reheat only the portion you plan to eat: cover it loosely and warm it in a 275°F (135°C) oven until heated through, checking often to avoid drying it out. You can also flake cold leftovers into a salad or grain bowl. Do not leave cooked fish at room temperature for more than two hours, and discard it if it has been stored improperly or shows signs of spoilage.
Frequently Asked Questions
How do I know when grilled swordfish is done?
Use an instant-read thermometer in the thickest part, inserting it from the side. The safe internal temperature is 145°F (63°C). At that point the flesh should be opaque and firm, with flakes that separate easily. Color alone is not a reliable safety check.
Can I make this on a grill pan?
Yes. Heat a lightly oiled grill pan over medium-high heat until hot, then cook the steaks for about 4 minutes per side, adjusting as needed for thickness. Ventilate the kitchen because the spices may smoke, and use a thermometer to confirm the center reaches 145°F (63°C).
Should I marinate swordfish before grilling?
No marinade is necessary for this recipe: the oil and dry spices season the surface without masking the fish. If you choose to use a separate acidic marinade, keep the fish refrigerated and limit the marinating time to about 30 minutes, as lemon or vinegar can make the surface soft.
Can I season the fish ahead of time?
You can mix the dry seasoning several days ahead and keep it in an airtight container. For the best texture, pat and season the fish shortly before grilling. If you season it in advance, cover and refrigerate it, and do not leave raw fish at room temperature while waiting.
Can I cook frozen swordfish steaks?
Thaw the steaks first for even cooking. The safest method is to thaw them overnight in the refrigerator, still wrapped or in a covered container. Pat them thoroughly dry before oiling and seasoning; surface moisture makes the crust harder to brown.
Can I freeze the leftovers?
Cooked swordfish can be frozen in an airtight, freezer-safe container for about 2 to 3 months, although its texture may become drier after thawing. Thaw it in the refrigerator and reheat gently, or use it cold in a salad. Do not refreeze fish that has been thawed at room temperature.