Peel the potatoes and cut them into medium-sized chunks.

Place them in a large pot and cover them with water. Bring the pot to a boil and cook until the potatoes are very soft, about 10-15 minutes.

While the potatoes are boiling, preheat the oven to 375 degrees F. Line 2 baking sheets with parchment paper.

Once the potatoes are cooked, drain the potatoes.

Pass the cooked potato through a potato ricer. If you don’t have a ricer, you can mash the potatoes with a potato masher; you want them as smooth as possible.

Add 4 Tbsp of butter and let it melt. Then mix in the cream, sea salt, and fresh ground pepper, taste, and adjust the salt and pepper if desired.

When the potatoes have cooled slightly, add the egg yolks and stir to combine.

Transfer the mashed potatoes to a pastry bag fitted with a large star tip. Working in batches, pipe the potatoes onto the parchment paper-lined baking sheets into swirls about 3 inches in diameter.

Melt the remaining 2 Tbsp of butter and gently brush the duchess potatoes.

Bake the potatoes for 20 -25 minutes, or until they have started to turn golden around the edges and the ridges on top.

Garnish with chopped parsley, chives, or fresh thyme.