Searing tuna steaks allows you to enjoy the rich flavour of the fish by locking the flavours inside. Tuna needs to be seared quickly and under high heat to ensure that the outside of the steaks cook adequately. Properly seared tuna will still have a pink middle that remains red and rare. The oil or butter added to the pan helps to sear the outside of the meat quickly, which keeps the inside of the tuna fish steak moist.
Remove the tuna steaks from the refrigerator. Allow them to sit out at room temperature for 1/2 to 1 hour before you begin cooking.
Use a paper towel to dry excess moisture from the tuna steaks. Simply pat the paper towel on both sides of the steak to remove marinade or condensation from the meat.
Add 2 tbsp olive oil or butter to the pan over medium-high heat. Tilt the pan to spread the oil or butter across the surface and coat the pan.
Place the tuna steaks on the hot pan. Do not crowd the tuna in the pan. Keep the steaks at least 3 to 4 inches apart to make sure they cook evenly.
Sear each side for two minutes. Do not move the meat around too much while it sears. Gently shake the pan after two minutes, and if the tuna steak releases from the surface, you can flip it on its other side. It is important to make sure that the edged are seared, but you want the inside of the tuna steak to remain rare.
Make a small cut in the centre of the tuna steak with a knife. Inspect the inside to make sure that the middle of the steak stays rare and red in colour.