Sweetened chestnuts, shelled (See recipe below. Store bought is fine)
☆ Kanten powder
☆ Syrup from the sweetened chestnuts
Chestnuts, shelled and skinned
Peel the sweet potatoes, slice into 1-1.5 cm half moons, then soak in water for about 10 minutes.
Drain the sweet potatoes (they can be wet), put in a heat-resistant dish, cover loosely in plastic wrap, then microwave for 6-7 minutes at 600W.
The sweet potatoes are done when a skewer pierced into the center comes out clean. Pass the sweet potatoes through a sieve to purée. This step is tedious, but essential to the taste of this dish, so persevere!
Roughly chop chestnuts into 5 mm cubes.
Heat milk, the syrup from the chestnuts, and kanten in a pan, bring to a boil, then reduce the heat and simmer for about 2 minutes while stirring. Dissolve the kanten powder while simmering.
Add sugar and salt and mix well until they have dissolved. Remove from heat, add puréed sweet potato, then knead together.
Fold in the chopped chestnuts, fill a mold with the mixture, wrap in plastic wrap, then press with a flat object, as if you were making pressed sushi.
When it cools down, chill it in the refrigerator. After 2 or 3 hours, after it is well-chilled and set, remove from the mold, cut into desired sizes, then serve.
To make the sweet chestnuts: Soak shelled and skinned chestnuts in water. Put in a sauce pan, add water, sugar, and salt, then heat.
Bring to a boil, cover and simmer for 15 minutes on low heat. Add mirin and simmer for 5 more minutes (without a lid) and allow to cool in the pan.
I used a 4.5 cm by 34 cm half moon mold. For molds without removable bottoms, I recommend lining the mold with plastic wrap.
They also turn out great pressed in a rose-shaped silicon mold! If you have silicon molds, give it a try.
Story Behind this Recipe
Chestnuts and sweet potatoes -- the bounties of autumn! I had a craving for sweet potato yokan, but wanted something different, so I added sweetened chestnuts and the result was amazing. A total success!
Once the sweet potato cools down, it's hard to strain, so keep the potatoes warm under the plastic wrap, taking out only as much as you can strain. Straining the potatoes is tiresome and tedious, but the texture is completely different with this step, so keep at it. For the mold, you can line a bento box in plastic wrap and use it as a mold.