Recipe from Signature Pasta, published by The Italian Table. By Chef Fabrizio Aielli
Bring 1 quart of water to a boil and drop in the potato; cook until tender when pierced with a knife, about 20 minutes. Drain, peel, and chop. In a saucepan, combine the shallot, potato, broth, and 1/8 teaspoon of the saffron; bring to a boil, and cook over medium heat for 15 minutes. Remove from the heat, and pour into a blender; add the remaining saffron. Process the mixture until it begins to emulsify, then add the olive oil in a thin steady stream while the motor is running; the texture should be creamy.
Meanwhile, bring 5 quarts of water to a boil. Drop in the asparagus and salt; cook 3 minutes, or until crisp-tender; remove to a bowl of cold water with a slotted spoon. Add the ditalini to the boiling water, and cook until al dente; drain. In a large saute pan, toss the ditalini with the potato puree, the drained asparagus, and the Mascarpone for 1 minute over medium heat. Spoon the ditalini onto a serving dish, shave the black truffle over them with a truffle slicer, and serve hot, sprinkled with the Parmigiano.