01 - 
                Cook pasta shells in a large pot of salted boiling water according to package instructions until al dente. Drain carefully and set aside to cool.
              
              
              
                02 - 
                Preheat oven to 375°F (190°C).
              
              
              
                03 - 
                Heat olive oil in a skillet over medium heat. Sauté onion and red bell pepper for 5 minutes until softened, then add garlic and cook 1 minute more.
              
              
              
                04 - 
                Add shredded chicken, Cajun seasoning, paprika, salt, and black pepper to the skillet. Stir to combine thoroughly, then remove from heat and let cool slightly.
              
              
              
                05 - 
                In a mixing bowl, blend the chicken-vegetable mixture with ricotta, mozzarella, and Parmesan cheeses until evenly incorporated.
              
              
              
                06 - 
                In a saucepan, melt butter over medium heat. Whisk in flour and cook 1 minute. Slowly whisk in milk and heavy cream. Add Cajun seasoning, garlic powder, salt, and pepper. Simmer, whisking frequently, until thickened and smooth, about 5–7 minutes.
              
              
              
                07 - 
                Spread half of the cream sauce in the base of a 9x13-inch baking dish. Fill each shell with the chicken-cheese mixture and arrange in a single layer over the sauce.
              
              
              
                08 - 
                Pour remaining sauce evenly over stuffed shells. Sprinkle additional mozzarella cheese over the top.
              
              
              
                09 - 
                Cover dish tightly with foil and bake for 20 minutes. Uncover and bake an additional 10 minutes until cheese is golden and sauce bubbles.
              
              
              
                10 - 
                Allow baked shells to rest for a few minutes. Garnish with chopped parsley before serving, if desired.