Step 1

Allow the tuna steak to come to room temperature by letting it stand for at least 20 minutes.

Step 2

Pat the tuna dry. Sprinkle it liberally with kosher salt and fresh ground black pepper on both sides to get a nice even coating (about 3/4 teaspoon kosher salt for 8 ounces).

Step 3

Heat the oil in a medium skillet over medium high heat.

Step 4

Add the tuna steak and cook 1 to 2 minutes per side, until lightly browned on the outside but still rare on the inside. The tuna will continue cooking while sitting. For a medium-rare tuna steak, the internal temperature should be 130 degrees Fahrenheit when measured with a food thermometer at the thickest point.

Step 5

Cool for 2 minutes. Then slice the tuna against the grain into ½-inch slices and serve immediately, with the sauce if desired.