Grilled Tuna Steak with Homemade Herb Garlic Butter

I just love the flavor of a thick tuna steak grilled over open flame and topped with a knob of homemade herb garlic butter.

This recipe is fast, flavorful, and extremely satisfying. You can make it with both fresh or frozen tuna, just make sure that your grill is hot enough!

Why Tuna Steaks Are My Favorite

Tuna steaks are a grill master’s dream—rich, firm, and perfect for searing on high heat!

Think of it as the steak of the sea. The dense, meaty texture holds up perfectly on the grill, developing a beautifully charred crust on the outside while staying juicy and tender at the center.

Why it’s perfect for grilling:

• Firm texture: Unlike flaky white fish, tuna holds its shape over high heat.
• Fast cook time: A 1-inch tuna steak needs just a few minutes per side—perfect for quick grilling.
• Versatility: Pairs nicely with bold seasonings or simple touches like compound butter.

When you want something different from the usual chicken or beef, tuna steak is a great choice, and it looks just as impressive on the plate.

Choosing the Right Tuna – Fresh vs. Frozen

Both fresh and frozen tuna steaks will taste fantastic when you have high-quality fish and it’s grilled properly.

Here’s what to look for when buying tuna:

• Fresh tuna:
  • Deep red or pink color (depending on species)
  • Moist, not slimy
  • Mild ocean scent (never fishy)
• Frozen tuna:
  • Look for individually vacuum-sealed steaks labeled “sushi-grade” or “for raw consumption”
  • Thaw in the fridge overnight or in a cold water bath (still sealed) for best texture
  • Once thawed, pat completely dry before seasoning or grilling
• Recommended size and thickness:
  • Tuna steaks that are about 1 inch thick work best for grilling
  • Uniform thickness helps ensure even grilling—no overcooked edges with raw centers

Step 1: Make the Herb Garlic Butter

This herb garlic butter is what turns grilled tuna from great to unforgettable.

It gives a rich and aromatic flavor that melts over the warm fish and makes every bite so delicious, you’ll feel it deserves its own standing ovation!

Ingredients:

• ½ cup salted butter, softened
• 1 garlic clove, very finely minced (use more if you like it punchy)
• 2 tablespoons finely chopped fresh parsley
• 1 teaspoon finely chopped fresh rosemary
• Optional: swap or add other herbs like basil, tarragon, or chives
• Pinch of salt, only if using unsalted butter

How to make it:

1. Add all ingredients to a bowl,
2. Mix until fully combined.
3. Spoon the butter onto a sheet of plastic wrap (cling film).
4. Roll into a cylinder and twist the ends to seal. Refrigerate for at least 20 minutes before using.

This butter can be made days in advance and stored in the fridge. Slice off rounds as needed to melt over grilled fish, vegetables, or even steak.

Step 2: Prepare & Season the Tuna Steaks

Tuna doesn’t need much to shine. A quick brush of olive oil and a generous sprinkle of salt and pepper are all it takes to bring out its rich, clean flavor and help develop a nice crust on the grill.

How to prep your tuna:

1. Pat the steaks dry with paper towels. This step is key for getting a good sear and preventing steam.
2. Brush lightly with olive oil on all sides. This prevents sticking and helps you get a nice browning.
3. Season generously with:
   • Kosher salt (or sea salt for texture)
   • Freshly cracked black pepper

That’s it, no marinades, no fuss! Your grill and the garlic herb butter will do the heavy lifting.

Step 3: Grill the Tuna

Tuna steaks are best grilled hot and fast, just like a good beef steak.

The goal is a beautifully seared exterior while keeping the center tender and slightly pink (or rare, if that’s your style). Overcooked tuna turns dry fast, so timing is important.

Grill setup:

• Preheat your grill to medium-high to high heat (about 450–500°F / 230–260°C).
• Clean and oil the grates just before placing the tuna to prevent sticking.

How to grill:

1. Place the tuna steaks on the hot grill and don’t move them for 2 minutes. This builds a crust and helps with clean flipping.
2. Flip once, using tongs or a fish spatula, and cook the other side for another 1½ to 2 minutes.
3. During the last minute, baste with herb garlic butter using a brush or spoon. Let it melt and sizzle into the surface for added richness.
4. Pull the steaks off the grill when the center is still slightly translucent—120°F (49°C) for rare, 130°F (54°C) for medium-rare.

If you want the tuna more well-done (you’re cooking for someone who doesn’t enjoy raw or pink fish), aim for 140°F to 145°F (60–63°C). But be aware that tuna cooked beyond this point will start to dry out, so be extra generous with the herb garlic butter to keep it moist and flavorful.

One option is to make thinner steaks for faster, even cooking if going for well-done.

Let the steaks rest for 2–3 minutes. A slice of compound butter on top while they rest will melt into the fish and finish the job!

Serving Suggestions – Plating, Sides & Finishing Touches

Tuna steak doesn’t necessarily need much to complete the plate. A knob of melting herb butter and maybe some grilled veggies will do it!

I served the tuna steaks with grilled veggie kabobs that I conveniently cooked right next to the tuna on the grill.

More sides that pair beautifully:

• Grilled asparagus or zucchini
• Lemon-herb rice or wild rice
• Crisp green salad with vinaigrette
• Grilled sweet potatoes or roasted baby potatoes

A Few More Tips & Variations

Even with a quick grill like tuna, small details make all the difference.

Here are some expert tips to help you get that restaurant-quality finish every time—and a few creative ways to mix it up.

Grilling Tips:

• Don’t walk away. Tuna cooks fast—just a few extra seconds can turn it dry. Stay close and use a timer.
• Start with dry tuna. Patting the steaks dry before oiling helps get that golden crust.
• Let the butter rest at room temp for a few minutes before slicing so it spreads more easily over hot fish.
• Use a fish spatula. It gives you better control and prevents tearing delicate edges.

Recipe Variations:

• Add lemon zest to the butter for citrus brightness.
• Use smoked paprika or a dash of cayenne in the butter for extra depth.
• Finish with a drizzle of balsamic glaze for a tangy contrast.
• Make it a tuna bowl—slice grilled tuna over rice with greens and a dollop of butter.

This recipe is a true grill master’s go-to: It’s simple, elegant, and easily adapted to your taste and occasion.

Enjoy grilling!

-Joonas