In a saucepan, heat the milk, butter, 1 teaspoon salt, and 1 teaspoon pepper over medium heat, just until scalded. Add the flour all at once and beat it vigorously with a wooden spoon until the mixture comes together. Lower the heat and cook, stirring constantly, for 2 minutes. Dump the mixture into the bowl of a food processor fitted with the steel blade. Immediately add the eggs, Pecorino, and Parmesan and pulse until the eggs are incorporated and the dough is smooth and thick.