Boil the potatoes: Start by boiling the potatoes in their skins in a large pot of salted water. Cook for 20-25 minutes, or until easily pierced with a fork. Drain and let cool slightly, then peel while still warm.

1. Mash the potatoes: Pass the peeled potatoes through a potato ricer or mash them well with a fork until smooth. Let them cool completely before proceeding to avoid a sticky dough.
2. Make the dough: On a clean surface, spread the mashed potatoes and create a well in the center. Crack the egg into the well and add salt and nutmeg (if using). Gradually incorporate the flour, mixing until a soft dough forms. Add more flour if the dough is too sticky. Knead gently until smooth.
3. Roll the dough: Divide the dough into 4 pieces. Roll each piece into a log about 1/2 inch in diameter. Use a knife to cut the logs into 1-inch pieces.
4. Shape the gnocchi: Roll each piece of dough down the tines of a fork to create ridges or press with your thumb to form an indentation. This helps the sauce adhere to the gnocchi.
5. Cook the gnocchi: Bring a pot of salted water to a boil. Drop the gnocchi into the water in batches. Once they float, cook for an additional 1-2 minutes, then remove with a slotted spoon.
6. Serve: Heat olive oil or butter in a skillet over medium heat. Sauté the cooked gnocchi for 2-3 minutes until golden and slightly crispy. Serve with your favorite sauce or toppings, such as pesto, tomato sauce, or brown butter and sage.