Preheat oven to 350 degrees. Prepare pasta shells, drain and set aside.Brown meat & onions w/ salt, papper, & garlic. Drain off any oil & put in a large bowl. Add cottage/ricotta cheese, and 1/2 bag of shredded cheese. Mix well. Stuff each pasta shell and line a 13" X 9" pan that you've sprayed w/ oil. Top stuffed shells w/ spaghetti sauce (I like Prego w/ Mushrooms)& remaining cheese.
Bake for 45 minutes until heated through and the cheesy is browning and bubbly. Let it set for 10 minutes if you can... Serve w/ a salad and garlic bread for rave reviews! I have never had anyone dislike this. It is definitely one of our favorite comfort foods.