The literal meaning of “tenkasu” is tempura refuse. I never really think of the meaning, so it is funny to realize the literal meaning of it. Sometimes it is also called “agedama,” fried balls. When you are frying tempura, there are always bits of flour batter floating, and those bits are scooped to the side often to keep the oil clean. By the end of the cooking, there is always some pile of it. It has probably no nutritional value, but a lot of people like it because of its crunchiness and its fullness of flavor. I don’t know who thought of it first, but people have been using tenkasu as a flavoring ingredient and a garnish in many dishes for a long time. It is a kind of similar idea as dried bacon bits or fried onion bits used to make a dish more flavorful in Western cooking. Tenkasu can be sprinkled on top of a salad, rice, noodles and almost anything you can imagine (I have seen tenkasu used as a garnish on top of a sushi roll in the U.S.) It just adds a nice extra flavor to a dish; so, it tends to be added to simple vegetable dishes that need some extra lift.
Tenkasu is available in the refrigerator or freezer section of any supermarket in Japan, but the best one if you can get it is the one you get at a tempura restaurant or a tempura shop. They are so crispy and tasty, and just so good. You can buy premade tenkasu at Japanese grocery stores in the U.S. too, but it can also be prepared at home pretty easily. And, it freezes well.
If you end up liking tenkasu, I have a great recipe with tenkasu for you also. This is called shrimp and tofu tenkasu donburi, which is a one-bowl “donburi” style dish with shrimp, tofu and tenkasu cooked in simmered sauce on top of rice. It is a great quick meal!
1/2 cup flour
1 tablespoon cornstarch
Pinch of salt
1/2 cup + 2 tablespoon water
2 teaspoon rice vinegar
Mix all the ingredients except the oil in a bowl. Pour the oil into a pan up to a height of at least 1 inch, and heat over medium-high heat. When the oil is hot, drop the flour mixture by using either a whisk, a few sets of chopsticks, or a few forks. You want to drop small pieces of flour batter, like rain drops to make small fried dough balls. I use a Chinese bamboo skimmer to make this process quicker. Scoop out the bits once they get a nice color, and drain on paper towel. If you want to make small balls, try not to crowd the pan so they don’t stick each other. But you can always break them into pieces once they have cooled off enough to handle. Let them cool completely, and freeze any that you don’t use right away.