Given the background description of some cooking related query, summarize the question into a title

[Q]: I'm reheating a bunch of leftovers, all stored in aluminum tins. I don't have enough oven rack space to lay it all out flat. Can I stack the tins?(Additionally, is it safe to leave on the paper/aluminum covers - the ones that are cardboard on one side and silver on the other?)
[A]: If I'm reheating things in tins and I don't have enough oven space, can I stack them on top of each other?

[Q]: I've heard that using a wooden chopping board for cutting meat is not very hygienic as it is a porous material. If that is the case, then what would a chopping board ideally be made out of when chopping meat?
[A]: Best chopping board material for meat

[Q]: I've read several question about slow cooking, but I don't know what is it and what it's good for. Can someone explain it? Thank you!
[A]:
What is slow cooking and what it is good for?