Preparation

• Preheat the oven to 350 F.
• Heat a thin layer of oil in a nonstick skillet over medium heat. Add the shrimp, crab meat, and 2 cloves minced garlic and cook until shrimp is pink and garlic is fragrant, about 2 minutes.
• Add the lemon juice and stir, then add the cream cheese cubes and stir until completely melted, about 3-4 minutes. Add the Old Bay seasoning, 1 tablespoon parsley, 1 teaspoon red pepper flakes, and a pinch each of salt and pepper. Stir to combine, then remove from the heat.
• Melt the butter in a deep skillet over medium heat. Once melted, add the remaining 2 cloves minced garlic and onion and cook until soft.
• Add the tomato paste and stir into the vegetables to combine. Cook until beginning to stick to the bottom of the skillet, about 3 minutes. Deglaze the skillet with the cognac, then bring to a simmer and reduce by about half.
• Add the tomato purée and heavy cream and bring to a simmer. Add the remaining red pepper flakes and parsley, then simmer until mixture is thickened, about 5 minutes. Season to taste with salt and pepper.
• Transfer the sauce to the bottom of a 9x13-inch casserole dish. Using a small spoon, stuff the shells with the crab mixture until full but not overstuffed. Arrange in the dish, nestling into the sauce.
• Grate the parmesan over the stuffed shells, then place in the oven and bake until cheese is melted, 20-25 minutes.
• Remove from the oven and sprinkle with parsley and red pepper flakes to serve.