Preheat oven to 375°F degrees.
Boil pasta shells until al dente.
Drain shells and set aside completely.
Mix ricotta, mozzarella, and Parmesan together.
Add beaten egg to cheese mixture.
Stir in fresh basil and parsley.
Season mixture with salt and pepper.
Spread half marinara sauce in dish.
Fill each shell with cheese mixture.
Arrange stuffed shells in baking dish.
Top with remaining marinara sauce evenly.
Bake covered for 25-30 minutes.
Remove foil and bake 10 minutes.
Let cool for 5 minutes before serving.