Bring a large pot of salted water to a simmer over high heat. In a large bowl, combine the ricotta, Parmesan, egg, egg white, parsley, nutmeg, salt, and pepper; mix thoroughly.
When the water is simmering and ready, stir the flour into the ricotta mixture. It is important not to add the flour too soon; otherwise they will become dense and gummy rather than light.
Shape the gnudi using 2 large soup spoons: scoop up a large spoonful of ricotta mixture into one spoon, then scoop the mixture onto the other spoon and back again, forming a three-sided oval. I have also seen these shaped into little round balls, like meatballs.
Drop the gnudi into the dredging flour. Form another 8 or 9 gnudi at a time, dredge in flour on all sides, and tap off the excess.
Slide the formed gnudi into the simmering water, being careful not to overcrowd the pot. Remove the gnudi using a slotted spoon after they have floated to the top and have cooked for about 4 minutes total.
While the gnudi cook, create another batch of gnudi and dredge them in flour. Continue cooking and forming gnudi, transferring cooked gnudi to a platter in a single layer, until you have used all the ricotta mixture.