Gnocchi With Mushroom Sauce

Directions

1. For gnocchi: Preheat oven to 450F. Pierce potatoes with fork. Bake till tender, about 1 hour. Cold slightly; cut potatoes in half and scoop pulp into large bowl. Mash potatoes well. Fold in egg yolk, salt, pepper and nutmeg. Fold in sufficient flour to create hard, slightly elastic dough. Turn out onto lightly floured surface. Divide dough into 4 equal portions. Gently roll 1 portion between hands and work surface to create 1/2-inch-thick rope about 18 inches long. Cut crosswise into 1/2-inch pcs. Roll each piece over tines of dinner fork to make grooves in gnocchi. Arrange gnocchi in single layer on floured baking sheet. Repeat with remaining 3 portions of dough.
2. Working in small batches, cook gnocchi in large pot of boiling salted water till gnocchi rise to top and are tender, about 5 min. Using slotted spoon, transfer gnocchi to large baking pan. (Gnocchi can be prepared ahead. Let stand 1 hour at room temperature, or possibly cover and chill up to 2 days.)
3. For mushroom sauce: Cook butter and extra virgin olive oil in heavy large skillet over medium heat till butter begins to brown, about 2 min. Add in mushrooms and shallots and saute/fry till golden, about 10 min. Add in stock and sage; simmer till liquid is slightly reduced, about 8 min. Season to taste with salt and pepper.
4. Add in gnocchi to sauce in skillet and cook till heated through, about 1 minute. Add in arugula and stir till wilted. Divide equally among bowls.
5. Drizzle with truffle oil, if you like. Sprinkle with cheese.
6. *Available at Italian markets, specialty foods stores and some supermarkets.
7. Makes 4 Servings.