The word imo is used in Japanese for many starchy root vegetables. There’s jagaimo (potato) and satsumaimo (sweet potato), both fairly recent additions to Japan’s diet, as well as its language. There’s also the yamaimo (mountain yam). But possibly the most familiar imo of them all is the satoimo (taro). The name satoimo means “village” or “homestead” imo, since it has been grown near villages (as opposed to the yamaimo, which was gathered in hilly areas) for millennia.
The taro originates in South or Southeast Asia, and is thought to have been introduced to Japan toward the end of the prehistoric Jomon Period (10,000-200 B.C.). It quickly adapted itself to the climate, and became a valuable staple food way before rice — or grain farming in general — was introduced. Although the zuiki (taro leaf stems) are eaten too, the corms are the main source of food.
Even after rice became commonly grown in Japan, it remained a food for the wealthy for a long time. Even in the comparatively recent Edo Period (1603-1868), the farmers who grew rice had to hand most of it in as nengu (land taxes), leaving little to none for themselves. So they grew other grains such as millet, as well as the satoimo, for their own consumption. From the 18th century onward, satsumaimo also became an essential staple on the mainland (it had already been present in the Ryukyu Kingdom, present-day Okinawa, for about a century). These days, it is grown all over the country with the exception of Hokkaido. The top producing prefectures in 2018 were Saitama, Chiba and Miyazaki. Specific type of taro are called other names besides satoimo: A type with a thin tapered shape grown in the Kyoto area is called ebi-imo (“shrimp imo”); another variety that is formed by several corms growing together to form one mass is called a yatsugashira (“eight heads”).
One thing to be aware of with taro corms is the presence of raphides, needle-shaped crystals of calcium oxalate that can irritate the skin when you are peeling them. To counteract this, you can hold the corms with a kitchen towel or paper towels. Dipping your hands or the corms in vinegar water will also lessen the irritating effect. (The calcium oxalate also makes the corms toxic when raw or untreated, which is why they need to be properly cooked. Don’t eat raw taro!)
The recipe here is for a classic inaka nimono, a hearty, country-style stewed dish with daikon radish and carrot, two other vegetables that are in peak season in the autumn. The chicken wings already provide lots of umami, so I have only used a little instant dashi to enhance the soup. This dish is great hot or cold, and works well in bento boxes as well as for dinner. A frying pan makes it a lot easier to make nimono, especially for beginners.
Recipe: How to make country-style taro and chicken nimono stew
Serves 4 as a side dish
Prep: 15 mins., cook: 35 to 40 mins.
For the nimono:
300 grams chicken wing pieces (about 8 to 10 wings)
400 grams taro root (about 8 corms)
1 10-centimeter piece daikon radish
1 medium carrot
1 large piece (about 2-centimeters long) ginger
3 medium spring onions, green parts only
½ tablespoon vegetable oil
For the seasoning:
½ teaspoon instant dashi stock granules
4 tablespoons sake
4 tablespoons mirin (sweet, fermented cooking alcohol)
3 tablespoons brown sugar
4 tablespoons dark soy sauce
1. Scrub the taro corms if they have dirt on them. Peel, holding them with a paper towel. Cut into about 2-centimeter-wide pieces. Place the pieces in a plastic bag with enough salt to lightly coat each piece. Seal the bag and squeeze to rub the salt over the surface of the taro. Put the pieces into a colander, rinse with water and pat dry. (The salt treatment makes the taro absorb flavors better.)
2. Peel the daikon radish, slice into 2-centimeter-wide slices and quarter them. Peel the carrot and cut into chunks about the same size as the daikon. Peel the ginger and cut into matchsticks. Cut the green onions into 3-centimeter-long pieces.
3. Heat up a large frying pan with the oil over medium heat. Add the chicken wings and brown them lightly. Remove the wings and wipe out the pan. Put the wings back in the pan along with the taro root, daikon radish and carrot. Add just enough water to cover. Add the dashi stock granules, sake, mirin and sugar. Bring to a boil, then lower the heat to a simmer. Cover the pan with a piece of kitchen parchment paper cut to fit just inside the pan, with a 1-centimeter hole cut in the middle, like a doughnut. Leave to simmer for 20 minutes.
4. Add the soy sauce and ginger and simmer for an additional 15 minutes.
5. If a skewer goes easily through a taro root piece, it’s done. Add the green onion and raise the heat to boil off a little more liquid (it should come up to barely half the height of the ingredients), gently shaking the pan. Serve hot or cold. This keeps for two to three days, well covered, in the refrigerator.