Grilled Swordfish with Coriander Lime Butter

Grilled Swordfish with Coriander Lime Butter

That loud hiss when the steaks hit the hot grate is the best part. Then comes the smell, a mix of charred fish and the sharp, bright scent of lime that cuts through the smoke. If you've ever had swordfish that felt like chewing on a rubber eraser, you know exactly why this approach is different.

I used to overcook this fish every single time because it looks so much like a beef steak. I'd wait for it to "look done," and by then, it was a brick. Now, I rely on a thermometer and a hit of compound butter to keep it juicy.

This Grilled Swordfish with Coriander Lime Butter is a weeknight hack for when you want something that feels expensive but doesn't require a whole day of prepping. It's fast, lean, and hits all the right notes.

Why This Mix Hits

Lean Protein: Swordfish has almost no internal fat, so it dries out the second it overcooks. Adding butter at the end replaces that lost moisture.

Citrus Acid: The lime juice breaks down the dense muscle fibers, making the fish feel less heavy on the tongue.

Recipe Specs

The key to this dish is high heat and a short window. You want a dark crust but a center that's still slightly translucent.

Precision Checkpoints

• Grill Temp: 450°F (230°C)
• Internal Temp: 130°F (54°C)
• Rest Time: 5 minutes

Ingredient Deep Dive

Avocado oil is a great choice here because it won't smoke or burn at 450°F the way butter would. I suggest using unsalted butter so you have complete control over the salt levels.

The Grocery List

• 2 (6 oz / 170g) swordfish steaks, roughly 1 inch thick
• 1 tbsp (15ml) avocado oil Why this? High smoke point avoids a burnt oil flavor
• ½ tsp (3g) kosher salt
• ¼ tsp (1g) cracked black pepper
• 4 tbsp (57g) unsalted butter, softened Why this? Helps infuse the fish with the lime and herbs
• 1 tbsp (3g) fresh coriander, finely chopped
• 1 tbsp (15ml) fresh lime juice
• 1 tsp (2g) lime zest, finely grated
• 1 clove (3g) garlic, mashed into a paste
• Pinch (0.5g) of sea salt

The Gear List

You don't need a professional setup, just a few basics that handle heat well.

• Gas Grill: Best for that over high heat sear.
• Instant Read Thermometer: Non negotiable. This is the only way to avoid rubbery fish.
• Paper Towels: To get the fish bone dry.
• Small Bowl: For whipping the butter.

Steps to Get it Right

Time to start cooking. The key is to leave the fish undisturbed on the grill so a proper crust can form.

Prepping the Butter

1. Combine the softened butter, minced coriander, lime juice, lime zest, garlic, and salt in a small bowl, whipping until the mixture is pale and smooth.
2. Leave this at room temperature so it doesn't lower the fish's temperature when added.

Searing the Steaks

3. Use paper towels to pat the swordfish steaks completely dry. Note: Surface moisture leads to steaming rather than searing.
4. Season both sides with avocado oil, salt, and pepper.
5. Get the grill preheated to high heat (approximately 450°F / 230°C).
6. Place steaks on the grates and sear for 4–5 minutes per side without moving them, until a mahogany colored char develops.

Finishing the Fish

7. Pull the fish off the heat when they hit 130°F (54°C) internally.
8. Immediately add a generous dollop of the coriander lime butter to each steak.
9. Rest the fish for 5 minutes. The butter will transform into a rich sauce and the core temperature will climb to a medium finish.

Fixing Common Issues

If the fillets cling to the grates, stay calm and resist the urge to pull them. Typically, the fish will let go naturally once the searing process is complete.

Preventing the Stick

This occurs when the grates lack sufficient heat or the fish is moist. Ensure the metal is shimmering before you start. If it's clinging, allow it another 60 seconds.

Avoiding Rubber Texture

Avoid overcooking at all costs. Just a couple of extra minutes can destroy the consistency. Remove the fish from the heat at 130°F to let the residual heat finish the job.

Butter Not Melting

Cold butter tends to stay in clumps. Ensure it is softened beforehand or keep your compound butter at room temperature while grilling.

Ways to Serve It

Since the Grilled Swordfish with Coriander Lime Butter is quite rich, you want sides that are light and acidic. I usually go with a charred asparagus bunch or a simple cucumber salad.

The Tropical Pairing

Serve this with mango salsa and coconut rice. The sweetness of the mango plays well with the coriander and lime.

The Low Carb Classic

Pair the steaks with sautéed spinach or roasted cauliflower. It keeps the meal light and high protein.

Quick Decision Guide

• Extra tang? → add 1 tsp extra lime zest
• More heat? → fold in a pinch of cayenne to the butter
• Lighter sauce? → swap half the butter for Greek yogurt

Keep and Freeze Guide

Swordfish is best eaten immediately, but you can save leftovers if you're not eating it all in one go.

Refrigeration

Store leftover fish in an airtight container for up to 2 days. The butter will solidify, so you'll need to reheat it gently.

Reheating Strategy

Avoid the microwave. It'll turn the fish into rubber. Instead, place the steak in a pan over medium low heat with a splash of water or a knob of butter. Cover it for 2-3 minutes just until warmed through.

Freezing Note

You can freeze raw swordfish for 3 months, but don't freeze the cooked steaks. The texture degrades significantly upon thawing.

Zero Waste Tip

Don't toss the lime shells. Toss them into your compost or use the leftover zest in a batch of cookies or a cake. Use any remaining coriander stems by finely chopping them into a pesto or a salad dressing.

Swap and Change

If you want a different flavor profile, you can easily tweak the butter. For a more savory, deep taste, you might like my Soy Ginger Grilled Swordfish instead.

Flavor Twist: Spicy Garlic Chili

Add 1 tsp of Sriracha or chopped red chilies to the butter. It adds a kick that balances the fat of the butter.

Flavor Twist: Honey Lime Glaze

Mix 1 tsp of honey into the coriander lime butter. The sugars will caramelize slightly as the butter melts over the hot fish.

Diet Swap: dairy-free

Use a high-quality vegan butter substitute. The lime and coriander are the stars here, so the swap is barely noticeable.

Diet Swap: Oven Grilled

If you don't have a gas grill, use a broiler. Set your oven to broil and place the steaks on a sheet pan. Broil for 5-6 minutes per side. For a different approach to butter sauces, check out this Swordfish Lemon Butter Sauce for pan searing.

Common Misconceptions

The notion that searing locks in juices is a misconception. Water evaporates during the cooking process no matter how you begin. The purpose of the sear is actually to enhance flavor by creating a caramelized crust that adds depth.

Many people also think that swordfish requires hours of marinating. Because the meat is so dense, long marinades often result in a mushy exterior without penetrating the center. A quick rub of salt and oil is all you need for a perfect crust.

While USDA guidelines state the safe internal temperature for fish is 145°F, home cooks generally aim for 130°F followed by a rest for a medium rare to medium finish.