The Secret to Grilling Tuna

Spice-Rubbed Seared Tuna Steaks

 The Spruce

The grill offers you two ways of preparing tuna. One method is to grill a thinner tuna steak over high heat until it is cooked through. The other method is to quickly grill it over very high heat, searing the outside. The second method may scare more than a few people since it leaves most of the fish raw, but seared tuna is an Asian favorite that's becoming more and more commonplace in the U.S.

guide to grilled tuna illustration
Illustration: Miguel Co. © The Spruce, 2018  

The Basics of Grilling Tuna

No matter how you prepare tuna, always look for a good cut of fish. This means that the color is a deep red and even without dark patches. Tuna is a fish that's great for grilling and is uniquely meaty and delicious. Luckily, it's also easy to cook.

Tuna is a very lean fish and tends to dry out quickly on the grill. While serving with sauce will help, if you cook tuna beyond medium rare it will be dry. To help combat dryness, you can also marinate the tuna. Anything with a lot of acid will tend to cook the fish before it hits the grill, so the marinade should be pretty mild. Use some high-quality olive oil, herbs, spice, and a small amount of lemon juice or flavored vinegar and marinate for just a few minutes while you heat up the grill.

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Fully Cooked Grilled Tuna

If you choose a piece of tuna that is about 1-inch-thick then it will grill in about 8 to 10 minutes, flipped once. This will cook through to the middle provided that your grill is good and hot. You want to remove tuna from the grill before the surface starts to get crusty and burns. Unlike beef, lamb, or pork, you do not need to let tuna rest before serving. Get it off the grill and onto the plate right away.

Seared Grilled Tuna

For seared tuna, try getting a super thick cut of tuna, about three inches thick. Prepare it simply with a light brushing of oil and some salt and pepper and preheat the grill until very hot. The big difference between grilling and searing tuna is that you need intense heat for searing. Some gas grills simply can not produce the heat to properly sear a piece of tuna. Your best option, in this case, is to use a heavy cast-iron skillet. The metal of the skillet will absorb the heat and you will get a good sear as long as you preheat the pan. If you trust your grill to produce the heat, then go straight to the grate; otherwise, use the skillet or a good heavy griddle.

Charcoal grills will allow you to bank up the coals close the grate to get the kind of intense heat you need. The reason you want this kind of heat is because you will be grilling the tuna for just seconds per side and leaving the interior raw. Sear your thick cut of tuna on all four or six sides for only about 45 seconds per side. This gives you a piece of tuna that has a fantastic seared crust all around and a heated but raw middle. 

How to Serve Grilled Tuna

If you've cooked your tuna through and it's a little dry, or you just want to add more flavor, serve it with a sauce or some kind of salsa. Mango salsa, ginger and lime sauce, or buttery lemon chive sauce all compliment grilled tuna nicely.

Slice seared tuna and serve it immediately with a nice wasabi sauce or a balsamic reduction. Either tuna can be served as is alongside grilled vegetables or rice, or as part of a Niçoise salad or bowl.