Chicken Alfredo Stuffed Shells

Name: Chicken Alfredo Stuffed Shells
Ingredients: 30 jumbo pasta shells; 1 pound skinless, boneless chicken breast halves; 1.5 teaspoons kosher salt, divided; 1.25 teaspoons ground black pepper, divided; 1 tablespoon olive oil; 0.75 cup ricotta cheese; 2 cups shredded Italian cheese blend, divided; 2 tablespoons chopped fresh flat-leaf parsley, plus more for garnish; 2 tablespoons heavy whipping cream; 2 cups heavy whipping cream; 0.5 cup unsalted butter; 2 cloves garlic, finely chopped; 1 teaspoon Italian seasoning; 2.5 cups freshly grated Parmesan cheese, divided