Preheat the oven to 200 degrees. In a large (1 gallon) metal baking pan, combine the mushrooms, bouquets, salt and vegetable oil. Stir to blend all the ingredients. Cover the pan with aluminum foil and place in the oven. Slow roast the confit for 1 to 1 1/2 hours, or until the mushrooms are soft and tender. Remove from the oven and drain the mushrooms, reserving the oil. Bring a pot of salt water to a boil. Cook the pasta for 3 to 4 minutes and drain. In a mixing bowl, toss the pasta with the mushrooms, truffle oil, cheese, salt, pepper, and chives. Serve the pasta immediately.