Peel and chop the potatoes into even chunks. Place them in a large pot of salted water and boil for 15-20 minutes until fork-tender.

Preheat your oven to 425°F (220°C). Line a baking sheet with parchment paper.

Melt 2 tablespoons of butter in a saucepan over low heat, then add the heavy cream and warm it gently.

Drain the potatoes and mash until smooth. Mix in the melted butter, warm cream, Parmesan cheese, salt, pepper, and egg yolks.

Transfer the potato mixture into a piping bag fitted with a star tip and pipe small mounds onto the baking sheet.

Brush the tops of the mounds with remaining melted butter and bake for 15-20 minutes until golden brown.

Sprinkle with freshly chopped chives or parsley and flaky sea salt, then serve immediately.