While your pasta cooks, melt butter in a 12 to 14-inch saute pan and continue cooking until golden brown color ("noisette") appears in the thinnest liquid of the butter. Add sage leaves and remove from heat. Add lemon juice and set aside. Drain the pasta, but leaving some cooking water, and gently pour into saute pan and return to heat. Add the cheese, toss to coat and serve immediately.
Recipe courtesy of Mario Batali