Beet and Ricotta Roll

Put the flour on a work surface and add the eggs and salt. Knead until you have a smooth, firm dough. Roll out into a thin sheet. Cook in boiling salted water, then remove and stretch out on a dish towel. Puree the beets with the beaten egg, ricotta, grated Parmigiano, grated nutmeg, salt and pepper until smooth. Spread out on the dough with a spatula. Roll up the dough and wrap in a clean dish towel. Boil the roll for a few minutes in salted water, then let cool. Cut into slices and arrange on a serving dish. Sprinkle with Parmigiano and melted butter. Serve.