Bring a large pot of water to a rolling boil and add a generous amount of salt. Once the water returns to a boil, cook the tagliolini according to the package instructions until perfectly al dente. Reserve a ladleful of the pasta water before draining.

While the pasta is cooking, gently clean the white truffle using a damp cloth to remove any traces of soil. Grate half of the truffle and set the rest aside for shaving later.

In a wide skillet, melt the butter over medium heat until it starts to foam but does not brown. Stir in the grated truffle along with one or two tablespoons of the reserved pasta water, allowing the flavors to infuse the butter.

Add the drained tagliolini to the pan and toss gently over low heat to coat the strands evenly with the truffle-infused butter. Sprinkle in some grated Parmigiano, if using, and continue to stir for less than a minute until everything is well combined.

Plate the pasta onto four pre-warmed dishes. Finish each serving with an extra touch of Parmigiano and freshly shaved white truffle on top. Serve immediately and savor the luxurious flavors. Buon appetito!