In a large bowl, combine the ricotta, 1/4 cup Parmigiano, egg, butter, salt, pepper, and nutmeg.  Sprinkle 3/4 cup of the flour over the ricotta mixture and fold it in.

Dust the dough lightly with half of the remaining flour and shape into a log about 2 inches thick.  Using the remaining flour, lightly dust work surface, roll the dough out to a rope about 1-inch thick.

Using a bench knife or dull butter knife, cut it into 1-inch pieces.  Transfer to a baking sheet lined with a non-stick baking mat or parchment paper.

In a large pot of boiling salted water, boil the gnudi until tender and cooked through, about 6 minutes; drain.

Spoon the gnudi and sauce into bowls.   Sprinkle with cheese and serve.