Preheat the oven to 350 degrees F.
Cook the pasta shells according to the package instructions and set them aside.
Meanwhile, prepare the chicken filling by combining the ingredients; ricotta cheese, chicken, egg, parmesan cheese, sour cream, cajun seasonings, Italian seasonings, black pepper, salt, and parsley. Mix it until well combined.
Stuff the shells with the prepared chicken mixture and set it aside.
Heat a skillet on medium flame, melt the butter and add minced garlic. Cook for a minute.
Stir in the heavy cream along with the parmesan cheese and cajun seasonings. Let it simmer for 4-5 minutes until the sauce slightly thickens.
Pour the sauce over the baking dish, arrange the stuffed pasta shells and sprinkle the mozzarella cheese on top.
Bake the stuffed shells for 18-20 minutes until the cheese has melted. Garnish the pasta with parsley and red pepper flakes before serving.