Bring a large pot of well salted water to a boil, and cook the shells a couple of minutes less than what the package tells you. Drain and drizzle with a little olive oil so they don't stick, and set aside. I like to lay them out single layer on a baking sheet or platter.
Keep your Bolognese sauce warm on the stove.
Mix together the ricotta, egg, 1 1/2 cups of the mozzarella and 1/2 cup of the Parmesan cheeses, along with the parsley in a large bowl and make sure it's all well combined. I add a teaspoon each of salt and fresh cracked black pepper, use more if you like.
Ladle a layer of sauce on the bottom of your baking pan. I used a round cast iron pan, but you can also use a 9x13 size casserole.
Fill each of the shells with the cheese mixture and place them in the pot, open side up. Wedge as many as you can onto the first layer, and add a second layer if you have to.
Cover the shells liberally with the sauce and bake for about 30 minutes, or until everything is hot and bubbling. Add the remaining cheeses to the top and bake for another 5 minutes, or until melted.
Serve hot with a sprinkle of chopped parsley or basil.
https://theviewfromgreatisland.com/stuffed-shells-with-bolognese-sauce-recipe/ February 17, 2017