Steamed "Graham" Potato Buns

I love steamed breads. Until now I associated them with Asian dumplings, but this recipe hails from the United States. It is a simple yeast dough made with milk, mashed potato, whole wheat flour* and white flour. After the bulk rise, it's divided into nine rolls and popped in the steamer for 30 minutes.
The result is a hearty yet soft, fluffy bread with a perfect biscuit-like texture on the inside. I have never been able to make good biscuits with whole wheat flour; they always come out gritty, crumbly and dry. The mashed potato and white flour (1 part white to 2 parts whole wheat) in this recipe make the buns smooth and light(er), and I would sub them in for biscuits any day. The steaming gives them a sweet, shiny skin that only dumplings have. They are equally good with butter and honey as with a saucy, savory stew. I'll be making these again for sure.

*The recipe called for graham flour, which is white flour with bran mixed in, but I substituted freshly ground whole wheat pastry flour.