Sweet potato jelly - Sweet potato jelly

Japanese: 芋ようかん - いもようかん

...For information on these sweets, which were sold by so-called baked sweet potato shops, please refer to the "baked sweet potato" entry. As sweets, various types are made, such as "imo natto," which is boiled down with sugar to make it similar to sweetened adzuki beans, and "imo yokan," which is strained, mixed with sugar, and hardened. A Western-style sweet potato is steamed, strained, and kneaded with butter, milk, egg yolk, and flavorings, then placed in a boat-shaped skin, brushed with egg yolk, and baked in the oven.

From [Yokan]

…Mizu-yokan is made soft enough to melt, and is a popular summer treat. Imo-yokan is made by steaming sweet potatoes, straining them, adding sugar, mixing well, and pressing them into a shallow wooden box. It has a unique, folk-friendly taste, and was called "Ryukyu-kan" in the Edo period. [Suzuki Shinichi]. …

*Some of the terminology that refers to "imo yokan" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…いわゆる焼芋屋が商ってきた，これらのものについては〈焼芋〉の項目を参照されたい。菓子としては，砂糖で煮つめて甘納豆のようにする〈芋納豆〉，裏ごしして砂糖などを加えて寄せかためた〈芋ようかん〉などいろいろのものが作られる。洋風のものでは，蒸して裏ごしにかけ，バター，牛乳，卵黄，香料などを加えて練ったものを，舟形に切った皮に盛り，卵黄を塗ってオーブンで焼くスイートポテトがある。…