When it comes to tuna steaks, a simple preparation is often the best. The real star here is the quality of the fish, so try to buy high-quality, sushi-grade tuna steaks if you're able. After all, tuna steaks are meant to be prepared so that the centers stay raw, while the sides boast a beautiful and decadent sear. In terms of seasoning, the most straightforward, and perhaps most delicious, preparation method is olive oil, salt, pepper, and lemon juice. Adding oil at the end will help to keep the moisture inside the tuna steak, as well as provide flavor. For an optimal sear, be sure to preheat your pan over high heat before adding the steak. You'll only sear the steak on each side until cooked about a quarter of the way up the sides. This can take anywhere between 30 sec. and 2 min., depending on the thickness of your steak. Keep an eye on it, as it can happen quickly, and overcooked tuna steaks can taste tough. Enjoy!