This simple-to-make recipe is guaranteed to bring you compliments- I would give it many more stars if I could. This creamy sauce is worth every bit of exercise you might feel compelled to do-- count your calories elsewhere, and just enjoy this dish! Your tastebuds will thank you! My recommendations: 1) You must use a full-bodied, dry white wine, as the sauce's end result relies on that. I recommend Mersault. 2) You should dedicate 20 minutes to making the sauce. The white wine, vinegar, shallot mixture should take at least that long to reduce, as it should gently boil over medium-high heat. Don't let it boil rapidly, but don't let it just simmer either. 3) Use about half the butter called for, or use all of the butter and let the sauce reduce. Experience has taught me that this sauce is always better when it is thicker and richer. If the recommended amount of butter is used, the result is a thin, mild sauce. By reducing the butter, you'll create a denser, creamier sauce that seems more appropriate for a thick tuna steak. 4) If you take my recommendation for cutting back on the butter, realize that this will reduce the amount of sauce you make to about 3-4 adult portions. 5) Lastly, I recommend serving this with orzo, freshly sliced tomatoes, and deep fried spinach (found on allrecipes.com). The colors, textures, and flavors blend very well.

What you want here is the sauce, as it's more delectably remarkable and delicious beyond any I have EVER encountered!! Use yellowfin or ahi/sushi grade tuna, thickly sliced. If you don't marinate it, at least cover it with olive oil then coat generously with black/white sesame seeds which have been combined with chopped fresh herbs such as Italian parsley, cilantro, basil, etc., whatever you may have on hand. Place the fish on wax paper and refrigerate for 30 minutes. Heat olive oil in a heavy skillet, and quickly sear the tuna on both sides (1.5 minutes), do not let the tuna cook or you destroy the true flavor (it's like eating the finest rare beef steak, you can't tell the difference). Served with the butter and wild rice/lemon pilaf or greens, it's total heaven! And all I do with the refrigerated leftover sauce and to cook another tuna meal is let the butter get to room temperature, scoop an amount on a plate, and set the hot fish upon it. Unless you reheat the butter VERY carefully and slowly, it will separate such as in a clarification process, changing its flavor and quality. This is absolutely my favorite meal!!!! TEN stars on the sauce, and wasabi away to your tasting!

This is one of the best recipes for seared ahi tuna. If you're watching fat and calories you can reduce the amount of sauce you put on the tuna or reduce the amount of butter as I did and it is still wonderful (I reduced both the amt of butter in the recipe and the amt of sauce i put on each serving, so figure 1C = 16T. I used 3/4C (12T) or so and used about 1/8 of that sauce on each serving (equates to less than 2T butter per serving). Recipe is also very simple and quick. Why spend more time on a more complex recipe that doesn't taste as good? Seared tuna can be somewhat sweet in flavor on its own and many recipes over enhance this. If I could give this more stars I would.