Two recipes for stuffed shells are spinach and ricotta-stuffed shells and easy stuffed shells. Both of these recipes require about 20 minutes of preparation time.
Start making spinach and ricotta-stuffed shells by preheating the oven to 400 F and placing the rack on the highest rung. Cook 20 jumbo shells, drain, and run under cold water. Take a large broiler-proof baking dish and coat with a 24-ounce jar of marinara sauce. Mix 2 15-ounce packages of ricotta cheese, 2 cups of chopped baby spinach, 1/2 cup of grated Parmesan cheese, 1/2 teaspoon of kosher salt and 1/4 teaspoon of black pepper. Sprinkle 1/2 cup of grated mozzarella over the top and bake for 10 to 12 minutes. Finish by changing the oven setting to broil and cooking for two to five minutes or until the cheese turns a golden brown.
To make easy stuffed shells, preheat the oven to 350 F. Cook 35 jumbo sized pasta shells according to the package directions. Coat a greased 13-by-9-inch baking dish with 1/2 cup out of a 24-ounce jar of spaghetti sauce. Thaw one package of 36 frozen, fully cooked Italian meatballs, 1/2-ounce each. After the shells cool, put one thawed meatball in each, and place the stuffed shells into the baking dish. Layer on the remaining spaghetti sauce and sprinkle with 2 cups of shredded part-skim mozzarella cheese. Cover and bake for 35 minutes, uncover and bake for three to five minutes more, until the cheese is bubbly.