Cut the pasta dough into maltagliati.
In a large pot of boiling, salted water, cook the maltagliati just until al dente, about 3 minutes.
Meanwhile, in a large, heavy skillet over medium-high heat, melt the butter. Stir in the mushrooms, season with salt and pepper and cook until browned, about 5 minutes; season again with salt and pepper. Stir in 1 cup of the pasta cooking water. Using a spider or small strainer, transfer the pasta from the pot of water to the skillet. Sprinkle with the cheese and chives; toss.
One Quick Trick for Cutting Chives