Grilled Marinated Swordfish Steaks With Avocado Butter: A Taste of Summer

The first time I tasted swordfish was on a tiny island off the coast of Sicily. The local fisherman, Salvatore, had just pulled his boat ashore, the morning’s catch glistening in the sun. He grilled the swordfish simply, brushed with olive oil, lemon, and herbs. The flavor, so fresh and clean, was a revelation. I’ve been chasing that taste ever since, and this recipe, with its vibrant marinade and creamy avocado butter, comes incredibly close to capturing the magic of that Sicilian morning. It’s a celebration of simple, high-quality ingredients, transformed by the kiss of the grill into something truly extraordinary.

Recipe Overview

• Prep Time: 25 minutes
• Cook Time: 18 minutes
• Total Time: 43 minutes + 2 hours marinating
• Servings: 8
• Yield: 8 swordfish steaks
• Dietary Type: Gluten-Free

Ingredients

• For the Swordfish Marinade:

  • 64 ounces swordfish steaks (approximately 8 steaks)
  • 1/2 cup vegetable oil
  • 1/4 cup soy sauce
  • 1 teaspoon lemon rind, grated
  • 1/4 cup fresh lemon juice
  • 2 cloves garlic, crushed

• For the Avocado Butter:

  • 1/2 cup butter, softened
  • 1/2 cup ripe avocado, mashed
  • 1/4 cup plus 1 tablespoon fresh lime juice
  • 2 tablespoons fresh flat-leaf parsley, minced
  • 2 cloves garlic, minced
  • 1/2 teaspoon salt

Equipment Needed

• Two 13 x 9 x 2 inch baking dishes
• Small bowl
• Small saucepan
• Grill
• Small mixing bowl
• Electric mixer (optional)

Instructions

1. Prepare the Swordfish Marinade: Place the swordfish steaks in two 13 x 9 x 2 inch baking dishes. This will ensure they are properly submerged in the marinade.
2. Combine Marinade Ingredients: In a small bowl, whisk together the vegetable oil, soy sauce, grated lemon rind, fresh lemon juice, and crushed garlic. Stir well to emulsify the mixture.
3. Marinate the Swordfish: Pour the marinade mixture evenly over the swordfish steaks, ensuring each steak is thoroughly coated. Cover the baking dishes tightly with plastic wrap and marinate in the refrigerator for at least 2 hours, turning the steaks occasionally to ensure even marination. The longer the marinating time, the more flavorful the swordfish will be.
4. Prepare the Reserved Marinade: Remove the swordfish steaks from the marinade, reserving the marinade in the baking dishes. Pour the reserved marinade into a small saucepan.
5. Simmer the Marinade: Bring the marinade in the saucepan to a boil over medium-high heat. Once boiling, reduce the heat to low and simmer for 5 minutes. Simmering the marinade will kill any bacteria and make it safe to use as a basting sauce. Set aside.
6. Prepare the Grill: Preheat your grill to medium-high heat. Make sure the grates are clean to prevent the swordfish steaks from sticking.
7. Grill the Swordfish: Place the marinated swordfish steaks on the hot grill grates. Grill for approximately 9 minutes on each side, or until the fish flakes easily when tested with a fork. Baste the steaks frequently with the reserved (and now simmered) marinade during the grilling process to keep them moist and add flavor. The internal temperature of the swordfish should reach 145°F (63°C).
8. Prepare the Avocado Butter: While the swordfish is grilling, prepare the Avocado Butter. In a small mixing bowl, combine the softened butter and mashed avocado.
9. Cream the Avocado Butter: Beat the butter and avocado together using an electric mixer at medium speed until smooth and creamy. Alternatively, you can use a fork to mash and combine the ingredients if you prefer a more rustic texture.
10. Add Flavorings to the Butter: Add the fresh lime juice, minced fresh flat-leaf parsley, minced garlic, and salt to the avocado butter mixture.
11. Combine the Avocado Butter: Stir well to ensure all the ingredients are evenly distributed throughout the avocado butter.
12. Chill the Avocado Butter: Cover the avocado butter and chill in the refrigerator until firm, about 30 minutes. Chilling allows the flavors to meld and the butter to firm up, making it easier to serve.
13. Shape the Avocado Butter (Optional): If desired, shape the chilled avocado butter into small balls or quenelles before serving. This adds a nice visual touch to the presentation.
14. Serve: Serve the grilled swordfish steaks hot, topped with a generous dollop of the avocado butter. Garnish with fresh parsley sprigs for an extra touch of freshness.

Expert Tips & Tricks

• Don’t Overcook: Swordfish can dry out easily if overcooked. Use a meat thermometer to ensure it reaches an internal temperature of 145°F (63°C).
• Marinate Smart: Avoid marinating for longer than 4 hours. The acidity in the lemon juice and soy sauce can start to “cook” the fish and make it mushy.
• Grill Prep: Oil the grill grates well to prevent sticking. You can use a high-heat oil like grapeseed or avocado oil.
• Flavor Boost: For an extra layer of flavor, add a pinch of red pepper flakes to the marinade.
• Avocado Ripeness: Use a perfectly ripe avocado for the butter. It should be soft enough to mash easily but not overly mushy.
• Make Ahead: The avocado butter can be made a day ahead and stored in the refrigerator. Just be sure to cover it tightly to prevent browning.

Serving & Storage Suggestions

Serve the grilled swordfish steaks immediately after grilling for the best flavor and texture. The creamy avocado butter melts beautifully over the hot fish, creating a rich and flavorful sauce.

Leftover swordfish can be stored in an airtight container in the refrigerator for up to 2 days. Reheat gently in a skillet over low heat or in a microwave. Be careful not to overcook it during reheating.

Leftover avocado butter can also be stored in an airtight container in the refrigerator for up to 2 days. However, it may discolor slightly due to oxidation. To minimize browning, press a piece of plastic wrap directly onto the surface of the butter before refrigerating.

Nutritional Information

Nutrient	Amount per Serving	% Daily Value
Calories	596.7 kcal	N/A
Calories from Fat	N/A	63%
Total Fat	41.7 g	64%
Saturated Fat	12.9 g	64%
Cholesterol	180.2 mg	60%
Sodium	937.2 mg	39%
Total Carbohydrate	7.8 g	2%
Dietary Fiber	1.1 g	4%
Sugars	0.7 g	2%
Protein	46.9 g	93%

Note: Percent Daily Values are based on a 2000 calorie diet.

Variations & Substitutions

• Spicy Swordfish: Add a pinch of red pepper flakes or a dash of your favorite hot sauce to the marinade for a spicy kick.
• Citrus Herb Marinade: Replace the lemon juice and rind with orange or grapefruit juice and rind. Add a sprig of fresh rosemary or thyme to the marinade.
• Dairy-Free Avocado Butter: Substitute the butter with a dairy-free butter alternative or coconut oil.
• Grilled Pineapple Salsa: Instead of avocado butter, top the swordfish with a grilled pineapple salsa for a tropical twist.
• Soy-Free Option: Use coconut aminos instead of soy sauce for a soy-free marinade.

FAQs (Frequently Asked Questions)

Q: Can I use frozen swordfish for this recipe?
A: Yes, you can use frozen swordfish. Just make sure to thaw it completely in the refrigerator before marinating and grilling. Pat it dry with paper towels before grilling to remove excess moisture.

Q: How can I tell if the swordfish is cooked properly?
A: The best way to check for doneness is to use a meat thermometer. The internal temperature should reach 145°F (63°C). The fish should also flake easily when tested with a fork.

Q: Can I make the avocado butter ahead of time?
A: Yes, you can make the avocado butter up to a day ahead of time. Store it in an airtight container in the refrigerator. Press a piece of plastic wrap directly onto the surface of the butter to prevent browning.

Q: What if I don’t have a grill?
A: You can also cook the swordfish in a skillet on the stovetop or bake it in the oven at 400°F (200°C) for about 12-15 minutes, or until cooked through.

Q: What are some good side dishes to serve with grilled swordfish?
A: Grilled vegetables like asparagus, zucchini, or bell peppers are excellent choices. You can also serve it with a side of quinoa, rice, or a fresh salad.

Final Thoughts

This grilled marinated swordfish with avocado butter is more than just a recipe; it’s an invitation to slow down, savor the flavors of summer, and create a memorable meal. The combination of the savory swordfish, the zesty marinade, and the creamy avocado butter is simply irresistible. I encourage you to try this recipe and experience the taste of sunshine on a plate. Feel free to experiment with different variations and substitutions to make it your own. And please, share your feedback! Let me know what you think and how you’ve adapted the recipe to suit your tastes. Pair this dish with a crisp Sauvignon Blanc for the perfect culinary experience. Bon appétit!