Satsumaimo no Amani (Sweet Simmered Japanese Sweet Potato)
If you want to enjoy Japanese sweet potatoes with an extra touch of sweetness, try this classic Japanese side dish called Satsumaimo no Amani. It is a perfect choice when you are in the mood for something sweet.
otoshi-buta (drop-lid) (You can easily make one by following the instructions above. If that seems like too much trouble, you can simply use a regular lid instead.)
Trim both ends of the sweet potato, then slice it into ⅖-inch (1 cm) thick rounds. Soak the slices in water (not listed in the ingredients) for about 5 minutes to remove any astringency.
Place the sweet potato slices in a pan or pot, arranging them so they overlap as little as possible. Then, add water (as specified in the recipe) and bring it to a boil. Once boiling, add mirin and sugar, cover with an otoshi-buta, and let it simmer over medium-low heat for 15 minutes.
Remove the otoshi-buta, add soy sauce, and continue simmering for a few more minutes. Turn off the heat and let the flavors meld for at least 20 minutes.
Notes
You can store it in the refrigerator for up to 4 days.