Stuffed Shells with Chicken and Arugula and Creamy Alfredo Sauce

Name: Stuffed Shells with Chicken and Arugula and Creamy Alfredo Sauce
Ingredients: 6 jumbo pasta shells (conchiglioni); 2 1/2 cups ricotta cheese; 1/2 cup grated Parmesan; 1 tablespoon olive oil; 2 cloves garlic, minced; 2 cups arugula; 2 cups chopped cooked chicken (rotisserie chicken works well); 1/2 teaspoon salt; 1/4 teaspoon ground black pepper; 4 tablespoons butter; 1 clove garlic, minced; 2 tablespoons all-purpose flour; 2 cups heavy cream; 1/2 cup milk; 3 tablespoons chopped fresh chives; 1 cup plus 3 tablespoons grated Parmesan; 1 cup grape tomato halved; Italian parsley for garnish