POTATO PUFFS
Makes about 21 small puffs (5 to 7 servings).
Note: A 1920s cookbook 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 purée. You can do that if you like, but we thought the potatoes were good without that step. 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. Adapted from "Kitchen Essays," by Agnes Jekyll (first published in 1922 by Thomas Nelson & Sons, reprinted in 2008 by Persephone Books).
• 1 medium onion, cut into 8 wedges
• 2 lb. Yukon Gold potatoes, peeled and cut into quarters, or into sixths if the potatoes are large
• 2 tbsp. unsalted butter
• 2 egg yolks, plus 1 whole egg
• 1/2 tsp. salt