seared sesame-crusted ahi tuna: a holy fish?

One of my favorite appetizers, at any restaurant, is seared ahi tuna (also known as yellowfin or albacora). There is something about the smooth texture and the deep, rich colour of a tuna steak. Maybe it's just because I'm in trendy Vancouver, where the ability to eat sashimi is crucial to move in fashionable yuppie social circles, but I like raw fish. Lightly seared to make a crust with that deep rich red remaining in the center - that is perfection in a steak - any steak actually (except for if I was to make a steak out of chicken, then that would just be bad, and very salmonella-y . . ).
Anne and I attended mass after work. I've been thinking of taking RCIA classes - there is something about Catholicism, just as there is something about Anglicanism for me. Perhaps it is the tradition, the order with which every action is done, and the meaning every word, every movement has. After communion (well, a blessing for me), I prayed to find a good tuna steak (seriously, I did! It isn't blasphemous to pray to find good food!), and God acquiesced.
There is nowhere better to buy fresh fish (near my house) than Granville Island Public Market (that, and its just an experience in and of itself every time I'm in there!).
I have an obsession when I walk around the Market - I have to look inside every stall, delving for spices, herbs, and odd ingredients I can't find in my 'normal' supermarket. One of my newest exclamation was 'kaffir lime leaves!!! I can't find these anywhere! Oh joy!' and my friends looking at me oddly as did a celebratory dance in the middle of the stall. They really can't take me anywhere, or at least anywhere concerning cooking. 
Supposedly, only one percent of tuna comes to the North American market fresh - the rest is canned. So it may be a little hard to find good ahi, but trust me, it can be done (especially in BC where sushi is all the rage). Tuna has been eaten since ancient times, yet it was only in the late 1800s that it was termed 'tuna'. But heck, it is a big fish - it can range from 10 - 600 lbs. - I have no idea how they would have caught that in ancient times, help from Hercules? I know, bad joke, but seriously, how.

The fish is full of omega-3 fatty acids, yet it is also full of mercury, so please, only partake once a month (and if pregnant, don't consume at all!)
It was delicious. An expensive triumph (fresh tuna is not only filled with mercury, it is also dang expensive - even more of a reason to savor only once a month!).
Seared Sesame-Crusted Ahi Tuna
(adapted from Use Real Butter Blog)

1 ahi tuna steak, 1/2 lb.
1/4 c. sesame seeds
1 tsp. salt
2 tsp. black pepper, coarsely ground
1 lime, juiced and zest(ed)
3 tbs. grapeseed oil

1/4 c. mayonnaise
1 tbs. wasabi powder
3 tbs. water

1/4 c. soy sauce
2 tbs. brown sugar
3 tbs. rice wine vinegar

salad stuff
avocado, sliced

1. Combine sesame seeds, pepper, salt, lime zest and juice in bowl. Dry the tuna steak with paper towel, then completely coat in the mix - press seeds and seasoning in.

2. Mix mayo, wasabi and water in a bowl until smooth, set aside. Mix soy sauce, brown sugar and rice wine vinegar in a small saucepan. Simmer until it has reduced - about a minute (and it thickens afterwards too! Remember that!).

3. Heat grapeseed oil over high heat in a cast iron frying pan. When it is hot (take some water on your fingers and flick it in - it should sizzle!). Place steak in, and sear for about 50 seconds on the large flat bottom and top, and about 20 seconds on the sides. Remove steak to a cutting board and slice into peices about 1/2 inch thick.

4. Set on a bed of greens or whatever salad stuff you choose. Drizzle plate with the mayo mix, and then the soy sauce mix.

5. Pray. Eat. Enjoy. Perhaps attend a mass.