Add flour and eggs to a bowl. Stir, then knead into a smooth and elastic dough. Cover the dough with a bowl, then set aside for about 30 minutes. Divide into four parts, and shape each piece separately while covering the rest with a bowl. Roll the dough to the thinnest thickness using a pasta machine. Then, cut into 4cm (1½ inch) rectangles. Take a pencil, and place its handle on one square of the dough. Fold its opposite ends over each other to get a fuži shape. Gently roll the pencil, then transfer the pasta to a baking sheet while working with the rest of the dough.
Place a pot with salted boiling water over high heat. Bring to a boil, then add the pasta. Cook until al dente, for about 3 - 4 minutes. Before draining the pasta, preserve 300ml (1 1/2 cups) of cooking pasta water if you plan on making the truffle sauce.
Place a pan over medium heat. Add oil and butter. When the butter melts, add the diced garlic. Saute the garlic for 30 seconds, then season with black pepper. Add the preserved pasta water and bring to a boil, then cook for 3 - 4 minutes or until about a third of the water evaporates and the sauce thickens. Reduce the heat to a minimum, and add the pasta. Toss to combine, then add the cheese while stirring continuously for the cheese to melt and the sauce become creamy. Lastly, stir in the black truffles or tartufata. Serve immediately.