Silicone cupcake liners are all you need

Silicone cupcake liners are the answer. Get a set of standard 2-inch flat-bottom silicone cups and use them as modular dividers inside any lunch container.

The easy way to hit five food groups without things touching: use the liners for the wet, messy, or strong-smelling stuff — protein, fruit, veg — and let the grain and dairy sit in the open sections of the box. If your box is just one big rectangle, five silicone cups will do the job on their own.

For best results, buy the flat-bottom kind, not the pleated foil-style ones. Look for food-grade silicone that holds its shape. Wilton and OXO both make them, and any generic set with smooth sides and a stable base works fine. The small 2-inch cups fit most lunch boxes; if you need bigger portions, silicone muffin cups work too.

One thing I’d avoid: the “leakproof” silicone cups with lids. They sound great, but they’re usually too stiff and bulky for packing tight, and they add nothing a piece of parchment or a regular cup won’t do.

This is not where you overthink it. Grab a set of cheap silicone liners, place them in a rough grid, and pack what you’d actually want to eat.