Cacio e Pepe Stuffed Shells

• 340g package of jumbo pasta shells 
• 4 tablespoons unsalted butter, melted 
• 2 cups heavy cream, room temperature 
• 1 tablespoon all-purpose flour 
• 1 1/2 cups Pecorino-Romano cheese, divided 
• 4 teaspoons ground black pepper, divided 
• Kosher salt 
• 450g ricotta cheese  
• 1 egg 
• 1 cup shredded part-skim mozzarella cheese, divided 

Preheat oven to 200°C.  

Cook the pasta shells in a Deep Casserole of boiling water until they are just al dente, about 8-10 minutes. Drain pasta and rinse under cold water to quickly cool. Shake dry and set aside. 

While the pasta cooks, mix melted butter with heavy cream, flour, 1/4 cup Pecorino-Romano cheese, and 1 teaspoon of black pepper. Season with salt and stir until well combined. Pour about 2/3 of the cream mixture into the bottom of a large baking dish with a lid and set aside. 

Place 1 cup Pecorino-Romano cheese, 2 teaspoons black pepper, ricotta cheese, egg and 1/2 cup mozzarella cheese in a large mixing bowl. Season with a large pinch of salt and stir to combine.  

Transfer the ricotta mixture to a piping bag (or plastic bag with a corner cut off). Carefully pipe the ricotta mixture into each of the pasta shells. Alternately, the ricotta mixture can be carefully spooned into the shells. Nestle stuffed shells on top of the cream mixture in the baking dish, then pour the remaining cream mixture over the top of the shells. Cover the dish with the lid and place it in the preheated oven. Bake for 10 minutes.  

Remove the dish from the oven and carefully uncover. Top the shells with the remaining 1/4 cup Pecorino-Romano cheese, 1 teaspoon of black pepper, and 1/2 cup of the remaining mozzarella cheese. Place the shells back in the oven, uncovered, and bake until they are just starting to brown and crisp on top and the cream sauce has thickened, about 20-25 minutes longer. Remove from the oven and let cool slightly before serving.