Heat oven to 375. Cook pasta according to directions, about 12- 15 minutes. Drain and rinse with cool water. Set aside.
Saute onion and garlic with olive oil until soft, add beef and cook until browned. Drain fat and set aside to cool.
In large bowl stir together cheese, eggs, parsley, basil, oregano and nutmeg. Salt & pepper to taste. Stir in cooled meat mixture.
Cover the bottom of a 13 x 9 inch baking dish with about 1/3 of the spaghetti sauce. Fill each cooked shell with about 2 tbsp of meat and cheese mixture and lay single file in dish. Pour remaining sauce over shells. Cover with foil and bake about 30 mins. Remove foil and bake an additional 10 min or until hot and bubbly.