I'm tackling tuna. Again. My last effort wasn't up to par for my tastes. I shouldn't use the word "tackle." That implies some sort of supreme effort. Sauteing a tuna filet is simple. You just need to pay attention. Like I say when cooking shrimp, don't overcook it. Take it off before you think it's done.
Here I have my lovely tuna filet, a bit thicker than my last one, seasoned with freshly ground salt and pepper. I have fresh parsley from my garden. And I have a mixture of: 1 part white sesame seeds 1 part black sesame seeds and less than 1/2 part red pepper flakes. I lightly toasted the sesame seeds and pepper flakes in a dry skillet. Important Note: This requires adequate ventilation. Don't say I didn't warn you!
I heated my iron skillet to medium high and added butter, for flavor, and a little oil, to raise the smoke point of the butter. You don't need Extra Virgin Olive Oil, just a regular canola, vegetable, safflower, or peanut oil.
Like I said, this filet was thicker than the last one - about 1 1/2 inches thick. I cooked it for 1 1/2 minutes each side.