A 1920s cookery book recommends these potatoes as a side dish for a pre-theater dinner. They would accompany a green vegetable, such as peas or green beans, on a serving platter.
In Edwardian times, there were no Yukon Gold potatoes -- they weren't widely available until 1980 -- but because they perform so well with this treatment, we don't feel guilty about being historically inaccurate. Also, back then the kitchen staff would have forced the potato-onion mixture through a fine sieve to obtain a smooth-as-silk puree. You can do that if you like, but we thought the potatoes were good without that step.
MAKE AHEAD: The potato mixture can be covered and refrigerated a day in advance; or the balls can be formed and rolled in the crumbs and then refrigerated, loosely covered, a day in advance. Bring to room temperature before baking.
Recipe By: "Kitchen Essays," by Agnes Jekyll (first published in 1922 by Thomas Nelson & Sons, reprinted in 2008 by Persephone Books).
Serving Size: 5
Yield: 21 small puffs