Stir together, sausage and ricotta cheese.
Add scallions, parmesan cheese, mozzarella cheese and parsley.
Pour some sauce in bottom of 9x13 dish to coat well.
Stuff each shell with filling and set in the sauce standing up.
Pour some more sauce over the tops of each shell.
Top with the remaining mozzarella and parmesan cheese.
Bake uncovered 20 -25 mins.