Then don't - get a small glass/Pyrex casserole dish with a glass lid and decant your leftovers into that every time you go to heat something up. I think IKEA sell some nice sized ones.

If you don't drop it they last for decades and that's what I've been doing. I do not reccomend looking for vintage stuff though - the reason why they stopped using the original original glass formula is because it chips easily and yeah, something that gets used on a very regular basis with its lid constantly going on and off is going to start chipping something awful over time