I’ve written about having ahi tuna at a restaurant, but I also like making it at home. Great ahi is expensive to buy, something like $20 a pound at Costco, but occasionally I treat myself and my wife to it.
Tuna fish in a can always disgusted me as a kid, but ahi is about as far from that as is possible for a fish with the same name to be. It is a wonderful meaty fish. It’s traditionally served rare, seared on the outside but with the center still red and wonderfully tasty. I use a salt-free Mrs. Dash teriyaki sauce for flavor when I cook it.
My wife likes hers cooked through, shunning anything cooked rare. Seafood chefs will warn you the tuna will dry out if over-cooked, so decide ahead of time what degree of doneness you really want, ahi is too expensive to overcook if that’s not what you want.
As a side dish, I like to slice portobello mushrooms and cook them down in the salt-free teriyaki sauce as well. The mushrooms are meaty in their own right and the teriyaki sauce gives them flavor they otherwise lack.
This all makes for a wonderfully decadent meal, perfect for a Friday night when you’re trying to leave all the grief of the workweek behind.
John
The No Salt, No Fat, No Sugar Journal 
I agree with your wife fully. I would also prefer mine fully cooked through, anything rare, gives me goosebumps. I’ve never eaten ahi tuna, leave alone heard about it. I shall be on the lookout. You make it sound so special, I’m so curious to taste it. Thanks for sharing!