Drain the beans in a colander, and rinse gently.
Place a fine strainer on top of a bowl, add a small amount of the beans at a time, and strain through using a pestle or similar. It's easier if you pour in some water to smooth it out.
Toward the end of straining, dip the strainer into the water in the bowl to loosen the last bean bits, so that only the skins remain in the strainer. Discard the bean skins.
Put the strained beans and the water in a cheesecloth and tightly squeeze the water out.
Put the beans from Step 4 and the granulated sugar into a pan and cook over medium heat.
Stirring constantly with a wooden spatula, knead well into a paste.
This is the brand of canned beans that I used.
One person told me that it is easier to strain the beans if you peel them at Step 2. Please give it a try.
Story Behind this Recipe
I wanted to make shiro-an (sweet white bean paste) for Japanese confections. So I made it from dried white kidney beans, but it took a long time to cook it until the beans were tender. Then I came up with an idea to use canned butter beans, and it came out better than I expected, so I decided to post it.
Please adjust the amount of the sugar to your preference.