What can you pack for lunch that's still good by midday?

The sad desk lunch is usually not a cooking failure. It is a timing failure. The salad was lovely at seven in the morning; by one o'clock the leaves have collapsed, the bread has gone limp and the dressing has pooled at the bottom of the box. The fix is to pack food that is designed for the wait, and to keep the fragile bits apart until the last moment.

Food that improves as it sits

Some dishes get better after a few hours, as flavours soak in and textures settle. Build lunches around them.

• Grain salads. Farro, barley, bulgur, couscous or rice, dressed while slightly warm so they absorb it, with roast vegetables, herbs, nuts and a crumbly cheese. Our grain salad page covers how to keep them lively.
• Bean and lentil salads. Chickpeas, white beans or lentils with red onion, lemon, olive oil and parsley. They drink the dressing and taste deeper by lunchtime.
• Roast vegetables. Peppers, aubergines, courgettes, squash, roasted the night before and dressed with oil, vinegar and herbs.
• Frittata and torta salata. Both are at their best at room temperature, cut into wedges, and travel well.
• Pasta salad, made with short, sturdy shapes and an oil-based dressing rather than mayonnaise, with things like olives, capers, cherry tomatoes and mozzarella.

Dress separately, or dress cleverly

Delicate things go soggy in contact with dressing. Two approaches:

• Separate pot. Keep dressing in a small jar and add it when you eat. Essential for leafy salads.
• Layer the box. Put the dressing at the bottom, then sturdy things that like a soak (beans, grains, cucumber, onion), then softer things, with leaves and herbs on top. Tip it into a bowl or shake it at lunchtime.

Crunchy toppings, such as toasted seeds, croutons and nuts, go in a separate small bag or tub. Sandwiches survive better with a thin layer of butter or oil-based spread on the bread as a barrier, with wet fillings like tomato packed separately or placed in the middle.

Think room temperature

Not every office has a microwave, and the queue for it is never inspiring. Plenty of food tastes better warm-ish than piping hot: roast vegetables, grain salads, frittata, a slice of tart, pasta salads, cold noodles with sesame dressing, a white bean and tuna salad, a good sandwich.

Take the box out of the bag a little before lunch if you want the chill to come off. More on the art of actually stopping to eat in taking a proper lunch break.

Keep it cold when it needs to be

Food safety comes first. The UK Food Standards Agency's picnic guidance lists cooked dishes, prepared salads and sandwiches, dairy, dips and lunchbox snacks among the foods that should be kept cool in a cool bag or box with ice or frozen gel packs. It also suggests spreading the ice packs around rather than leaving them all at the bottom, and keeping the bag closed and out of direct sun. If there is a fridge at work, use it.

In hot weather the same FSA page is stricter: in extreme heat, use food that has been out of the fridge within two hours. Plan lunches accordingly on hot days, or keep them chilled until you eat.

Containers worth having

• Leak-proof boxes with a proper seal.
• Small jars for dressings and sauces.
• A wide, shallow box for salads, so they don't get crushed into a dense mass.
• An insulated bag and a couple of flat ice packs.
• A good fork that lives in your bag, not a plastic one.

A few weekly directions

Cook once on Sunday, eat well till Wednesday:

• A pot of farro plus a tray of roast vegetables: three different salads with different dressings and cheeses.
• A big frittata with greens: wedges with a tomato salad, in a sandwich, or with beans.
• A pot of lentils: with roast carrots and yoghurt, with feta and herbs, or folded into a wrap.