Heat a pot of salted water to boiling then add the pasta shells. Cook until just tender, then drain and run under cold water to stop the cooking process.
While the shells are cooking, heat the meatballs. I place them on a plate, single layer and microwave on high for 2 minutes, roll them around then microwave again for 1 minute.
Preheat your oven to 180 C (350 F). Grease a 9x13 pan with butter. Spread 1/2 cup pasta sauce on the bottom of the pan. Place a meatball in a shell and place in the pan.
Repeat until all the shells are stuffed and placed in the pan.
Pour the pasta sauce over the shells.
Top with the shredded cheese and sprinkle with Italian seasoning as desired.
Cover with foil, place in the oven and bake for 35 minutes. Remove the foil and bake for 5 more minutes or until bubbly.
Remove from the oven, serve, and enjoy.