Ingredients
Method
- Preheat your oven to 375°F and lightly grease a 9x13 inch baking dish with butter or cooking spray.
- Place the peeled potato chunks in a large pot and cover with cold water by about an inch. Add a generous pinch of salt, bring to a boil, then reduce to a simmer and cook until the potatoes are fork-tender, about 15-20 minutes. Drain well and return them to the hot pot.
- Let the drained potatoes sit in the empty pot off heat for 10 minutes to release excess steam — this is crucial for getting good texture. The potatoes will look slightly shrunken and feel a bit drier on top.
- Mash the potatoes with a potato masher or ricer until smooth, then stir in the butter, heavy cream, egg yolk, salt, and pepper. Mix well until everything is fully incorporated and the mixture looks glossy and uniform. The mashed potatoes should be thick but still pliable — not runny.
- Spread the mashed potatoes evenly into your prepared baking dish or, for more elegant presentation, transfer to a piping bag and pipe mounds onto the dish using a star tip (a spoon works fine too). Make sure there's about 1/2 inch between each mound so they can brown individually without merging.
- Sprinkle the Parmesan cheese evenly over all the potatoes, then drizzle the melted butter on top in thin streams — you want coverage but not pooling.
- Bake for 30-35 minutes until the tops are golden brown and crisp at the edges. The center should be hot and set when touched lightly with a finger. If you want more color, switch to broil for the last 2 minutes, watching closely so the cheese doesn't burn.
- Let rest for 5 minutes before serving — they'll firm up slightly as they cool. Serve immediately while hot.
Nutrition
Notes
The trick is getting the mashed potatoes dry enough so the egg won't steam them from underneath. I learned that the hard way my first time, when my mounds collapsed into puddles in the oven. Now I spread the potatoes on a sheet pan and let them sit for ten minutes before piping or spooning them onto the baking dish — it makes all the difference.
I keep these in rotation because they're impressive enough to serve at dinner parties but simple enough that I can make them while someone else handles the rest of the meal. They hold up well reheated, too, which is a bonus when you have leftovers after guests leave with half their portion.