Dice the sweet potatoes into 7 mm cubes and soak in water.
Put the strained sweet potatoes into a heat-resistant dish. Cover with plastic wrap and microwave for 4 minutes at 600 W.
Mix the anko into the microwaved sweet potatoes.
Try not to mash the potatoes.
Separate into 8 portions.
Put the shiratamako into a heat-resistant bowl and gradually add water while stirring.
Stir until the shiratamako dissolves and becomes thick and syrupy.
Lightly cover with plastic wrap and microwave for about 2 minutes. Remove and stir well. It should look like the picture when you take it out.
Since it's still stiff, use some force and stir.
Microwave it a second time for 2 minutes. Stir it well. It will have become pretty smooth.
Microwave it a last time for 1-1.5 minutes. Stir it. It should be transparent. The stretchy dough is finished. It should be nice and soft.
Dust a pan with lots of katakuriko, transfer the dough, and coat more on top.
Use a bench scraper to divide into 8 portions.
Stretch it out to be as round as possible and lay the Step 5 portion over like a blanket. Covering from the top makes it easier to stretch.
Stretch the dough to cover the bottoms. Coat with katakuriko and it's complete.
You can see through the transparent dough.
They remain soft the next day.
Story Behind this Recipe
I combined several recipes I found on Cookpad and made a spin off.
Step 2: For the sweet potatoes, don't mash or pass through a sieve to smoothen. Leave them cubed when microwaving. Step 5: The mixture will be easier to form into balls if you put a little bit of water in your hands. Steps 8-11: If you place a damp towel underneath the bowl when you're stirring, the bowl won't move. Step 12: It's hot, so be careful. Coat quickly with katakuriko.