Potato Blinis

Preheat oven to 425°F. Prick potatoes all over with a fork and bake on a rimmed baking sheet until very tender and a knife slides easily through flesh, 60–70 minutes. Let cool slightly. Reduce oven temperature to 200°F.

Meanwhile, whisk egg yolks, egg, and sour cream in a medium bowl to combine; set sour cream mixture aside.

Cut potatoes in half lengthwise and scoop flesh from skins; discard skins. Pass flesh through food mill or ricer fitted with the small-hole disk into a large bowl. Working quickly, sprinkle flour, salt, pepper, baking soda, and nutmeg over potatoes; toss lightly with a fork to distribute ingredients, fluff potatoes, and break up any clumps. Make a well in the center and pour in reserved sour cream mixture. Whisk in a circular motion, working from the center out to incorporate, just until smooth (it should look like a thick pancake batter). Cover; let sit 10 minutes.