Creating Duchess Potatoes is simple if you follow these clear steps:

1. Preheat the Oven: Preheat your oven to 400°F (200°C).
2. Boil the Potatoes: Peel and cut the Yukon Gold potatoes into even chunks. Place them in a large pot of salted water and bring to a boil. Cook until tender, about 15-20 minutes.
3. Drain and Mash: Drain the potatoes and return them to the pot. Mash them until smooth and free of lumps.
4. Add Ingredients: Stir in the softened butter, heavy cream, egg yolks, salt, black pepper, and nutmeg (if using). Mix until well combined and creamy.
5. Incorporate Cheese: If desired, fold in grated Parmesan cheese for added richness and flavor.
6. Pipe the Potatoes: Transfer the potato mixture to a piping bag fitted with a large star tip. Pipe the mixture onto a baking sheet lined with parchment paper in swirls or rosettes.
7. Bake: Place the baking sheet in the preheated oven and bake for 25-30 minutes, or until the tops are golden brown and crispy.
8. Garnish: Remove from the oven and garnish with fresh herbs if desired.

These steps will guide you in creating these incredible Duchess Potatoes effortlessly!