Preheat the oven to 375 degrees F.
Place the hazelnuts on a sheet tray and brown in the oven for 10 minutes. Remove from the oven, allow to cool until it is comfortable to handle them, then slip them from their skins.
Place the nuts in a small, heavy-bottomed saucepan, pour the chicken stock over and bring to a boil. Boil for 5 minutes, then remove from heat and allow to cool.
In the bowl of a food processor, combine the nuts and stock, apple, heavy cream and salt and pepper, to taste. Blend until well combined but not completely homogenous. Set aside.
Bring 6 quarts of water to a boil and add 2 tablespoons salt.
In a 12 to 14-inch saute pan, place the hazelnut sauce and bring to a simmer over medium-high heat, taking care not to scorch it.
Meanwhile, drop the gnocchi into the boiling water and cook until they float aggressively, about 2 minutes. Drain the gnocchi, reserving the pasta cooking water, and add the gnocchi to the pan. Toss over high heat 1 minute to coat, adding a splash of pasta cooking water if necessary to keep the sauce from getting too ?tight.? Serve immediately garnished with grated cheese.
Boil the whole potatoes until they are soft (about 45 minutes). While still warm, peel and pass through vegetable mill onto clean pasta board.
Set 6 quarts of water to boil in a large spaghetti pot. Set up ice bath with 6 cups ice and 6 cups water near boiling water.
Make well in center of potates and sprinkle all over with flour, using all the flour. Place egg and salt in center of well and using a fork, stir into flour and potatoes, just like making normal pasta. Once egg is mixed in, bring dough together, kneading gently until a ball is formed. Knead gently another 4 minutes until ball is dry to touch.
Roll baseball-sized ball of dough into 3/4-inch diameter dowels and cut dowels into 1-inch long pieces. Flick pieces off of fork or concave side of cheese grater until dowel is finished. Drop these pieces into boiling water and cook until they float (about 1 minute). Meanwhile, continue with remaining dough, forming dowels, cutting into 1-inch pieces and flicking off of fork. As gnocchi float to top of boiling water, remove them to ice bath. Continue until all have been cooled off. Let sit several minutes in bath and drain from ice and water. Toss with 1/2 cup canola oil and store covered in refrigerator up to 48 hours until ready to serve.
In a large, heavy-bottomed saucepan, heat the oil over high heat until smoking. Add all the chicken parts and brown all over, stirring to avoid burning. Remove the chicken and reserve. Add the carrots, onions, and celery to the pot and cook until soft and browned. Return the chicken to the pot and add 3 quarts of water, the tomato paste, peppercorns, and parsley. Stir with a wooden spoon to dislodge the browned chicken and vegetables bits from the bottom of the pan. Bring almost to a boil, then reduce heat and cook at a low simmer until reduced by half, about 2 hours, occasionally skimming excess fat. Remove from heat, strain, and press on the solids with the bottom of a ladle to extract out all liquids. Stir the stock to facilitate cooling and set aside. Refrigerate stock in small containers for up to a week or freeze for up to a month.
Recipe copyright 2000, Mario Batali. All Rights Reserved.