Evan A. Sultanik, Ph.D.

Evan's First Name @ Sultanik .com

Chief Scientist
Digital Operatives, LLC

Adjunct Professor
Drexel University College of Computing & Informatics
Department of Computer Science

粤式蒸鱼 (Steamed Fish with Hot Oil)

In which I adulterate a classic Cantonese dish.

Steamed fish that is finished with a drizzle of hot oil is a classic Cantonese dish. The way I like to make it includes a few Japanese ingredients, and my method is a bit unorthodox.

Hardware

• 12 inch frying pan with lid
• A small raised rack that will fit inside the pan that can provide a centimeter or so of clearance above the bottom of the pan; the removable rack that came with my toaster oven works perfectly
• A very small bowl
• A small saucepan (it can be tiny)
• A platter for serving that is large enough for the fish and deep enough to hold some sauce

Software

• 2 tbsp. soy sauce
• 1 tbsp. mirin
• 1 tbsp. shaoxing cooking wine, or you can substitute an additional tbsp. of mirin
• 1 tbsp. sake
• 1/4 cup of either water, katsuo dashi stock, or water plus half of an instant dashi stock packet
• 1 fillet of a large flaky fish. Approximately 1 pound. I often use rockfish or wild striped bass. If you cannot find a large fillet, a smaller whole fish can be used.
• 1/4 cup coarsely chopped cilantro
• 2 in. knob of ginger, peeled and julienned
• 2 scallions, both whites and greens, julienned (or thinly sliced at an oblique angle, similar to the thicker Chinese "horse ear" cut)
• hot chili pepper, sliced thin at an oblique angle (optional)
• 1/8 tsp. five spice powder
• 1/4 tsp. toasted sesame oil
• 2 tbsp. vegetable oil

Algorithm

• Mix the soy sauce, mirin, shaoxing wine, sake, and water/dashi in the frying pan
• Place the fish into the pan and marinade for 15 minutes, flipping once half way
• Meanwhile, combine the ginger, cilantro, scallion, optional chili pepper, five spice and toasted sesame oil in a small bowl and mix
• Remove the fish from the marinade, place the rack into the pan, and the fish onto the rack
• Bring to a boil
• Once boiling, cover the pan tightly, reduce the heat to simmer, and steam for 8 minutes
• Meanwhile, start heating the vegetable oil in the small saucepan
• When the fish is done steaming, remove it and the rack from the pan, placing the fish on the platter
• Increase heat to high and let the sauce reduce to the consistency of Grade A (runny) maple syrup
• Pour the sauce over the fish and put the herb mixture on top of the fish
• When the vegetable oil is very hot, spoon it over top of the herbs

Lenticrypt: a Provably Plausibly Deniable Cryptosystem

or, This Picture of Cats is Also a Picture of Dogs

Back in 2009, I wrote about a thought experiment on how to subvert copyright law via plausible deniability. A couple years ago I expanded on that thought experiment by proposing a seedling idea on how to accomplish it via cryptography. Since then, I've slowly been developing that seedling into a functioning proof-of-concept, which has culminated in the creation of the Lenticrypt project:

Lenticrypt can generate a single ciphertext file such that different plaintexts are generated depending on which key is used for decryption:

$python lenticrypt.py -e key1 plaintext1 -e key2 plaintext2 -o output.enc$ python lenticrypt.py -d key1 output.enc | diff - plaintext1 -s
Files - and plaintext1 are identical

Streams Data Processing Workshop

A Presentation Introducing Distributed Combinatorial Optimization

I will be presenting a talk introducing distributed combinatorial optimization at the Streams Data Processing Workshop tomorrow. Here are the slides:

Handouts for the talk are also available, here.

Sushi Elitism

Three reasons why you've probably never had an authentic sushi experience.

There are a number of myths and misconceptions surrounding both the creation and consumption of sushi that I'd I think are important enough to devote an entire blog entry toward their clarification.

Proper sushi has a small amount of wasabi applied to the underside of the fish. Some people claim that "it is to prevent parasites" (via the natural anticeptic properties of the wasabi), but I find this explanation a bit dubious (I would think that the wasabi would have to be uniformly applied to the entire fish to have any measurable effect). The wasabi is really there to add flavor. In really high-end sushi restaurants in Japan, for example, it is relatively uncommon for the guest to be served a mound of grated wasabi; that's the sushi equivalent to serving an un-tossed caesar salad with the dressing on the side. Instead, the chef applies the perfect amount of wasabi to each piece of sushi. Some chefs will not even serve soy sauce, instead individually brushing on the sauce on each piece. If wasabi is served separately from the fish, it is generally also considered bad form to mix it with the soy sauce (as is commonly done in the US).

So, why might you have never seen this before at your local sushi joint?

1. It takes more time/skill/effort to do it properly.
2. Many sushi restaurants in the US do not have properly trained sushi chefs. In fact, in most areas of the country with little or no Japanese population, don't be surprised if your sushi chef is a Salvadorian who learned from the Oaxacan who learned from the Korean owner of the restaurant. Not that there's anything wrong with that; one of my favorite sushi places is run by an Indonesian. Just keep in mind that the people making you your sushi may have never experienced the "real thing" themselves.
3. "Real," fresh wasabi is very rare and expensive. Most of the stuff that is used in the US is basically horseradish paste plus food coloring. Restaurants that can both procure and afford to use the real stuff will want to use it sparingly; they wouldn't want to waste it by putting a mound of it on each plate. Therefore, they might be more inclined to use the "proper" technique.

Here is a video in which you can see famous chef Naomichi Yasuda using wasabi inside the sushi. It all happens very quickly, but you can clearly see him dip into the bin of wasabi, rub it on the underside of the fish, and then apply the fish to the rice. Here is another video in which Anthony Bourdain explains the "rules" of high-end sushi eating, while dining at the super-famous and super-expensive Sukiyabashi Jiro (the proprietor of which is actually designated as a "living treasure" by the Japanese government). That second video shows the chef brushing on the soy sauce, and the general lack of both soy and wasabi on the plates.

And on to the matter of chopsticks. Some purists claim that you're not supposed to use them, instead using your hands. I've been to Japan, and it really varies by the type of establishment. Here is my take on it: I think it really depends on the formality of the restaurant. In the more formal places, they won't serve any separate wasabi or soy (only gari) and they'll give you a small moist towel (in addition to the oshibori) that you are supposed to use to clean your fingers between pieces of sushi, under the expectation that you will use your hands. If they don't give a towel to clean your fingers, then I think it is acceptable to use chopsticks.

When I say "high-end", I mean a place that specializes in just sushi. In Japan, these places are usually tiny, consisting of only a bar. Each sushi chef services at most 5 customers at a time. Each chef is supported by perhaps one apprentice (who might prepare some of the seafood) and several other apprentices in the kitchen whose primary job is to prepare the rice. Sushi is all about the rice, after all; an apprentice will spend the better part of the first decade of his training just learning how to cook the rice, before even touching any seafood. That's why most casual restaurants in Japan (e.g., izakaya) will forego even serving sushi, instead offering preparations that require less skill/training (e.g., sashimi).