There are few foods on the planet for which you expend more energy chewing it than you receive in calories. Raw celery is one of them. Konnayaku, the Japanese product made from a plant in the taro family called konnayku (also referred to as konjac or devil's tongue), is my low calorie food of choice.
Konnyaku is as close to zero-calorie food you'll find—the majority of the gelatinous block is water, solidified with the addition of pulverized konnyaku powder and sometimes seaweed powder. Packages of konnayaku will range from literally zero to a whopping ten calories, depending on the brand. And, with no sugar, no fat, and no protein, blocks of konnyaku really are like the intimation of food. If you ever gone the whole day eating mostly konnyaku, you've probably experienced the strange sensation of being full but still slightly hungry at the same time—an empty, pure fullness that's just enough to keep you going.
Though the virtues of konnyaku are usually touted by dieters or select Japanese food lovers, konnyaku should be appreciated not only for its low-caloric features, but also because it's delicious. Konnayaku may be completely devoid of flavor, yet no other food product has its unique chew—a delightful, bouncy texture that's interesting enough to be the highlight of a a soup or simmered dish, though it often takes a back seat in sukiyaki and oden stews.
The taro root for konnyaku is old (it's allowed to mature for years before harvesting) and heavy, weighing as much as five pounds per root that can grow as large as six inches in diameter. The root is peeled, dried, and ground to a powder. The powder is then combined with water and some kind of coagulating agent, usually hydrated calcium, to set the mixture into a firm cake. Shirataki is simply gelatinous konnyaku mixture that has been shaped to look like noodles, though its texture bears no resemblance.
While some recipes for konnyaku or shirataki specify a brief cooking time, I prefer to cook my konnyaku for at least one and half hours so that the full flavors of the simmering liquid can be absorbed. Beef is a time-efficient complement to konnyaku, since both the meat and the pieces of konnyaku will take a while to cook. Hearty vegetables, such as daikon and lotus root, also pair well with konnyaku if the latter is allowed to simmer beforehand in a soup or stock.
Whenever I prepare konnyaku, I always cook a large pot of it so that extra slices of konnyaku—already cooked and flavored with the simmering liquid—may be charred in a cast iron skillet or set under the broiler. Doing so adds one more textural dimension to an otherwise uniform item: The surface of the konnyaku, when charred, will develop a slightly crisp and crackled skin.
Finally, there's another type of konnyaku that is meant to be eaten raw. You'll find packets of sashimi konnyaku alongside the regular stuff, though the sashimi konnyaku is presliced and often green or yellow depending on whether it's been flavored with seafood or citrus additions. Sashimi konnyaku is usually enjoyed with a little wasabi paste and soy sauce or a sweet miso and mustard sauce. Unlike the konnyaku that must be cooked, the texture of sashimi konnyaku is much more tender, though still chewy. On a hot day, sashimi konnyaku is just as refreshing as a salad yet considerably more filling.
Simmered Konnyaku with Beef
1 block konnyaku or 1 package shirataki 4 ounces stewing beef, cut into 1/2 inch cubes 3 tablespoons cooking oil or fat, for pan-frying 3 cups dashi 2 tablespoons each of soy sauce, mirin, and sake 1 teaspoon sugar 2 tablespoons brown or red miso paste, or to taste
Bring a medium-sized pot of water to boil. Add the whole block of konnyaku or the package of shirataki and parboil for 10 minutes. Drain and discard the water.
Cut the konnyaku lengthwise into two rectangular blocks, then cut each block into pieces 1/2-inch thick. Score each piece in a cross-hatch pattern to allow the flavors of the simmering liquid to penetrate more deeply. Set aside. If using shirataki, set aside.
Place a heavy pan, such as a cast iron skillet, over high heat. Add cooking oil or fat to the pan. Add the cubed beef to the pan and lightly brown on two sides; then remove with a slotted spoon. Using the remaining fat in the pan, lightly saute the parboiled and drained konnyaku or shirataki so that the surface is blistered and slightly browned. Remove and set aside.
Place the beef and the konnyaku or shirataki along with all the marinade ingredients into a medium saucepan. Bring the pot to a boil; then lower the heat to a simmer and cook for 1 to 1 1/2 hours, until the beef and konnyaku are tender. For a vegetarian option, substitute daikon and lotus root for the beef and add the vegetables during the latter half of simmering.
Add the miso paste to the simmering liquid and stir to dissolve. Simmer for a few minutes, correcting for taste. Depending on how salty your soy sauce and miso paste are, you may need to add a teaspoon or more of sugar. Serve hot.
Note: The squares of konnyaku may be browned in a hot cast iron pan, or set under the broiler for a few minutes to recrisp the surface.