Prepare the Roasted Red Pepper Coulis: Roast red bell peppers until blackened. Place in a bowl, cover with plastic wrap, and let steam for 10 minutes. Peel, seed, and roughly chop the peppers. In a blender, combine roasted peppers, Garlic, Olive oil, Red wine vinegar, and Red pepper flakes. Blend until smooth. Season with Salt and pepper to taste.
Prepare the Manicotti Shells: (Requires separate recipe - not included here for brevity).
Prepare the Filling: In a medium bowl, combine Ricotta cheese, Egg yolk, Grated Pecorino Romano cheese, Finely chopped fresh basil, diced Prosciutto, Sea salt, and Freshly ground black pepper. Mix well.
Stuff the Manicotti: Carefully fill each Manicotti shell with the Filling mixture.
Assemble and Bake: Spread a thin layer of Roasted Red Pepper Coulis in the bottom of a baking dish. Arrange the stuffed Manicotti shells in the dish. Pour the remaining Coulis over the Manicotti.
Sprinkle with torn fresh mozzarella and grated Parmesan cheese. Bake at 375°F (190°C) for 25-30 minutes, or until bubbly and golden brown.
