I remember the first time I did that I stuffed the sauce into the shell instead of the cheese mixture...
* 2 dozen large pasta shells
* 2 teaspoons salt
* 24 ounces part skim ricotta cheese
* 1/4 cup fine dry bread crumbs, Italian seasoned
* 1/2 cup grated Parmesan cheese, divided
* 2 tablespoons chopped fresh parsley or 2 teaspoon dried parsley flakes
* 1 egg, slightly beaten
* 1 medium onion, halved and sliced
* 2 cloves garlic, crushed
* 1 can (15 ounces) diced tomatoes, undrained
* 3 cans (8 ounces each) tomato sauce
* 1/2 teaspoon dried oregano leaves
* 1/2 teaspoon dried basil leaves
* 1 1/2 to 2 cups shredded Mozzarella cheese
PREPARATION:
Cook shells in boiling salted water, following package directions. Drain in a colander and rinse with cool water. Set aside. In a medium bowl, combine ricotta cheese, bread crumbs, 1/4 cup Parmesan cheese, 1/4 teaspoon salt, parsley, and egg; mix until well blended. In a large skillet, heat oil over medium heat; add onion and sauté until golden in color. Add garlic, tomatoes, tomato sauce, oregano, and basil; mix well and bring to a boil. Reserve 1 cup of sauce. Pour remaining sauce into a 9x13x2-inch baking dish. Carefully spoon cheese mixture into shells; arrange shells, opening side up, in tomato sauce in the pan. Pour reserved sauce over shells. Cover tightly with foil and bake at 375° for 30 minutes. Sprinkle with Mozzarella cheese and remaining 1/4 cup Parmesan cheese. Return stuffed shells to oven and bake, uncovered, 10 to 15 minutes longer. Stuffed shells serves 6.