Begin by peeling and chopping the potatoes into equal-sized chunks. Cover them with cold water in a large pot and bring to a boil, then reduce to a simmer for 15-20 minutes until fork-tender.

Drain the potatoes thoroughly and return to the pot over low heat for 2-3 minutes to evaporate moisture. Mash until completely smooth.

Incorporate butter and heavy cream into the mashed potatoes while warm. Add egg yolks, salt, pepper, and nutmeg. Stir until airy and fluffy.

Preheat the oven to 400°F (200°C). Transfer the potato mixture into a piping bag and pipe into swirls on a parchment-lined baking sheet.

Bake for 20-25 minutes until tops are golden brown and crisp. Broil for an additional minute if needed.

Let cool slightly before serving. Enjoy warm alongside your favorite main course.