Get an insulated food jar with a flat lid.

A wide-mouth insulated food jar with a flat lid is the best lunch box for a minimalist who wants one container, hot or cold.

The trick is the flat lid. Most thermoses come with a lid that doubles as a cup, which is pointless — that’s a second part you don’t need. Flat-lid versions cost a bit more, but you can eat straight out of the jar, so the whole thing is one stainless steel vessel.

I’d go with Hydro Flask’s 10 oz or 16 oz Food Jar with Flat Lid. MiiR’s 18 oz is also good. Both keep food hot or cold for six hours, are actually leak-proof, and don’t smell like last week’s chili. The 10 oz is right for a normal lunch; grab the 16 oz if you have a serious appetite.

The tradeoff? You can’t microwave it, and it won’t hold a sandwich plus a side plus a dessert without becoming a weird pile. If that matters to you, you need a Pyrex Snapware