Jar spaghetti sauce of your choice
Mozzerella String Cheese
Shredded Italian Cheese blend
Spray your baking dish. Slide a string cheese into your manicotti shell. Line a baking dish with them. Dump on sauce. Top with shredded cheese. Bake until shells are al dente.
If you're feeling ambitious, you can pre-boil the shells. Then you only have to bake for 30 minutes to melt the string cheese a little, and brown the cheese on top. :)