If you’ve got leftovers in a casserole dish that you’d like to just pop into the oven, prevent the food from drying out by sticking a small (oven safe) dish of water in the empty part of the casserole and putting the lid (or some foil) on the casserole when you heat it. The moisture from the evaporating water will prevent your noodles or veggies from drying out while they reheat. I used a ramekin in the photo above, but any small oven safe dish will do.