the middle rack of the preheated oven.
Bake, covered, for 30 minutes. Carefully remove the foil (watch for steam) and check the pasta by stirring gently from the bottom. The shells should be mostly tender but may still have a slight bite, and the sauce will look loose at this stage.
Return the dish to the oven, uncovered, and bake for another 10–15 minutes, stirring once halfway through if you like, until the pasta is fully tender and the
