Sausage-and-Kale Stuffed Shells

Name: Sausage-and-Kale Stuffed Shells
Prep time: 30 min
Total time: 30 min
Cuisine: European, Italian, Mediterranean
Ingredients: 6 ounces jumbo shells (from a 12-ounce box); Kosher salt and freshly ground pepper; 2 teaspoons extra-virgin olive oil; 4 ounces spicy Italian sausage, removed from casing; 2 cups chopped kale leaves (from 1 small bunch); 1.5 cups ricotta cheese (12 ounces); 6 tablespoons freshly-grated Parmigiano Reggiano; 8 ounces low-moisture mozzarella, grated (2 cups); 3 cups Three-Ingredient Marinara or your favorite jarred sauce (such as Rao's)