Patate Duchessa al Parmigiano (Italian Duchess Potatoes) Story of the Dish Duchess potatoes are a refined baked potato preparation made from a very dry, enriched potato purée piped into decorative shapes and baked until the ridges become golden and crisp. The potato base must contain as little excess moisture as possible so the rosettes hold their shape in the oven. Egg yolks provide stability and color, Parmigiano Reggiano adds savory depth, and butter enriches the potato wi