Glass meal prep containers bake fine — just ditch the lid.

Most lunch boxes can’t handle oven heat, but a glass meal prep container with an oven-safe base is actually a decent stand-in for a casserole dish.

The catch: the lids. That plastic lid that snaps on top? Not oven-safe. It’ll warp or melt. So if you want to bake in it, you’re baking uncovered, or you cover it with foil. That’s fine for most casseroles and baked pasta — you often want it uncovered anyway to get that crispy top.

“Completely safe” is doing a lot of work here. You need to check the bottom of the container for an oven-safe symbol and a max temperature. Pyrex and most borosilicate glass meal prep containers will say “oven-safe up to 400°F” or something similar. But don’t just assume all glass is safe — cheap glass can shatter under oven heat.

Also, thermal shock is real. Don’t take a container straight from the fridge and put it into a screaming-hot oven. Let it warm up a bit on the counter first. And when it comes out of the oven, let it cool before you put it in the fridge — hot glass on cold shelves is how you get broken dinner on the floor.

For reheating later, the microwave is the easiest and safest move. If you want to re-crisp the top, the oven works too, just follow the same temperature limits and never heat it with the lid sealed.

Ceramic and stoneware containers are also oven-safe and might feel more like a casserole dish, but they’re heavy for a lunch bag and you’ll pay more. So my take: a good glass meal prep container is your best bet.

Read the label, lose the lid, and don’t shock the glass. That’s the whole secret.