And by the end, that watery sauce reduces down into a lovely thick pasta sauce!
Not dissimilar to cooking pasta in a pot of boiling water, actually. The trick is simply to start with a large volume of watery sauce that the pasta shells cook in. It’s the way I’ve been cooking cannelloni/manicotti all my life. There’s no need to suffer through all that! It’s much easier to stuff raw, uncooked pasta shells and cook them in the oven simply by covering them in a LOT of sauce. Slipper suckers that they are, and they break so easily. I don’t know if you’ve ever tried, but stuffing hot cooked pasta shells is a nightmare. Serve with a Mega Italian Salad and garlic bread for the perfect dinner. These jumbo shells, called conchiglioni in Italian, are stuffed with spinach and ricotta. Such a pain messing around with hot floppy shells! Just bake in loads of sauce and they’ll cook in the oven.
There’s no need to pre-cook shells before you stuff them.