How to Make It
Preheat the broiler. In a large ovenproof skillet, heat the olive oil with the butter. Add the mushrooms and shallots and cook over high heat, stirring occasionally, until browned, 12 minutes. Add the vermouth and cook until evaporated. Add the stock, cream and thyme, season with salt and pepper; bring to a boil.
Meanwhile, in a large pot of boiling salted water, cook the gnocchi until they float to the surface, about 3 minutes. Drain well. Add the gnocchi to the mushrooms and simmer, stirring, for 1 minute. Stir in 1/4 cup of the Parmesan and sprinkle the remaining 2 tablespoons of Parmesan on top.
Broil the gnocchi 6 inches from the heat for 2 to 3 minutes, until golden and bubbling. Drizzle with truffle oil and serve.