Preheat the oven to 350 degrees F.
Bring a large pot of salted water to a boil. Add the pasta shells and cook for half the cooking time on the package; make sure not to overcook. Drain and rinse in cool water. Set aside.
In a bowl, mix together the ricotta, Romano, parsley, basil, egg, some salt and pepper and half of the Parmesan. Stir until combined.
To assemble, coat the bottom of a baking dish with some sauce. Fill each half-cooked shell with the cheese mixture and place face-down on the sauce. Repeat with the shells until the cheese mixture is gone. Top the shells with the remaining sauce. Sprinkle on the mozzarella and extra Parmesan.
Bake until hot and bubbly, 25 minutes. Serve with crusty French bread.