Marinara Sauce

1. Add a tablespoon of oil to a skillet and heat over medium heat.
2. Add the onion and cook until soft, about 4-6 minutes.
3. Add the garlic and cook for an additional minute.
4. Pour in the crushed tomatoes, Italian seasoning, salt, pepper, and red pepper flakes and bring to a simmer.
5. Reduce heat and gently simmer for 15-20 minutes. This will help it thicken.

 Cheese Filling

1. Mix the ricotta, parsley, Italian seasoning, pepper, salt, egg, and parsley together.
2. Add both cheeses and mix until combined.

Assembly

1. Preheat the oven to 350°F.
2. Boil a salted pot of water and add the noodles. Boil the noodles for 2 minutes then gently strain them. They are very difficult to fill and also get too soft in the oven if they are cooked through before filling and baking.
3. Rinse with cold water to cool them and prevent them from sticking.
4. Pour and spread about 1- 1 1/2 cups tomato sauce on the bottom of a 9x13 baking dish and set aside.
5. Add the cheese filling to a pastry bag (or a zip top plastic bag), cut the tip, and fill each par-boiled shell full (about 3 tablespoons). Alternatively, you can simply use a spoon and your fingers to fill the shells.
6. Place each shell in the baking dish and line them side-by-side in 2 rows. Continue until all shells are filled.
7. Pour remaining sauce over the stuffed shells, cover with foil, and bake until pasta is tender, about 45-55 minutes.
8. Uncover, top with parmesan and mozzarella cheese and bake an additional 10-15 minutes until cheese is melty.
9. Sprinkle with additional parsley and serve. Enjoy!