In the bowl of a stand mixer fitted with a whisk attachment, combine all ingredients for the Truffle Butter. Mix until light and fluffy. Transfer to an airtight container and refrigerate.
Bring a pot of salted water to a boil. Drop gnocchi and cook until gnocchi float to the surface. Strain, reserving pasta water.
In a pan over medium heat, add 3 ounces Truffle Butter and enough reserved pasta water to thin. Once warmed through, add cooked gnocchi. Toss to coat in butter.
Add Parmigiano-Reggiano and cook until cheese has melted and is well incorporated. Season with black pepper.
Transfer to a serving plate. Top with Pecorino Romano PDO and chives.
