Get a food jar, not a lunch box.

If you want soups and stews to arrive hot and leak-free, skip lunch boxes and get an insulated food jar.

A lunch box with a hinged lid is not built for liquid. That little silicone seal works until your bag gets knocked over, and then you’ve got chicken noodle soup in your laptop compartment. A food jar has a screw-on lid with a proper gasket, and it doubles as a thermos. It keeps things hot until noon, which a plastic box won’t.

The two worth your money are the Zojirushi Stainless Steel Food Jar — the one with the “rock lock” lid. It’s genuinely leak-proof, keeps soup screaming hot for hours, and cleaning isn’t terrible. If you don’t want to spend Zojirushi money, the Thermos King food jar is the budget pick that still does the job. Both come in sizes around 16–24 oz, which is the right amount for a proper lunch.

One caveat: don’t fill them to the absolute brim. Leave a little air gap for pressure, and you’ll avoid the lid being stuck or soup shooting out when you open it. Also, if you’re carrying soup cold (gazpacho, etc.), these still work — but you’re paying for insulation you don’t need. Glass containers with snap-lock lids are fine for cold stuff, just not for hot.

Future you doesn’t want a bag full of minestrone.