Special equipment: 2 pieces cheesecloth (for homemade Ricotta Cheese)
Preheat the oven to 350 degrees F.
Bring a large pot of water to boil. Cook the shells according to the package instructions, making sure to cook them a bit al dente.
Gently fold together the ricotta, Parmesan, parsley, salt, pepper, eggs, lemon zest and 1 cup of the mozzarella in a bowl. Fill the cooked shells with 1 tablespoon of the ricotta mixture each. Spoon a layer of the Tomato Sauce on the bottom of a 9-by-13-inch baking pan, about 2 1/2 cups. Place the filled shells on top of the sauce; do not overcrowd. Top the shells with the remaining 1 cup Tomato Sauce. Sprinkle with the remaining 1 cup mozzarella.
Cover with foil and bake for 25 minutes; remove the foil and cook until the cheese is fully melted and browned on top, an additional 5 minutes. Finish with chopped parsley and serve.
Bring the milk, half-and-half and salt to a simmer in a saucepan. Mix in the lemon juice and let the mixture sit off of the heat until curds form. Line a sieve with 2 pieces of cheesecloth and place it over a medium bowl.
Pour the milk mixture into the sieve and allow it to drain into the bowl for 20 to 25 minutes. Discard the liquid in the bowl occasionally so the sieve is not sitting in the liquid. The longer you let the mixture drain, the thicker the ricotta will be.
Use immediately or refrigerate in a covered container for 4 to 5 days.
Preheat the oven to 400 degrees F.
Put the beef bone on a rimmed baking sheet and roast for 30 minutes. Set aside.
Drizzle 3 tablespoons of the olive oil on a separate rimmed baking sheet. Add the tomatoes cut-side down in a single layer. Drizzle the tops of the tomatoes with an additional 3 tablespoons olive oil, sprinkle with 2 teaspoons salt and 1 teaspoon pepper and add the parsley. Roast until tender, 25 to 40 minutes. Transfer the tomatoes and parsley to a blender and puree until smooth. Set aside.
Heat a large stockpot on high heat and add the remaining 3 tablespoons olive oil. Add the garlic and saute for 1 minute. DO NOT let the garlic burn. Add the reserved tomato puree and bone to the pot. Simmer for 45 minutes to 1 hour, stirring occasionally. Season with additional salt and pepper.