In 3 tbsp. hot oil in large skillet, sauté 1 cup onion and 2 cloves garlic, 5 minutes, until tender; remove to a large mixing bowl.
In same skillet, brown beef, stirring occasionally.
Use a hamburger chopper to break meat up into small pieces while frying.
With slotted spoon, transfer beef to onion mixture in mixing bowl.
Add egg, salt, herbs, pepper and 1 ½ cups sauce.
Add 8-oz. shredded mozzarella cheese; stir into meat mixture.
With small spoon, fill raw, uncooked manicotti with meat mixture.
Preheat oven to 350°.
Spoon 1-2 cups sauce in bottom of two 10x15” baking pans.
Arrange 3 rows of manicotti lengthwise (8 across).
Cover with remaining sauce; sprinkle with Parmesan cheese.
Bake, covered with foil for 1 hour or 1 hour 15 minutes.
Mixture will start bubbling.
Remove foil, divide 8 oz. shredded mozzarella over the tops of shells in both pans.
Bake, uncovered, an additional 10 minutes or until cheese melts.
This makes about 35-40 shells – enough to serve at a large family gathering and put one pan in the freezer for later.