The news that Britons throw away a third of their food presents a curious anomaly. Ask any number of people to name their favourite dish and the answers are bound to include shepherd’s pie or bread and butter pudding — both traditionally made with leftovers. Today they are bought ready-made: worlds away from their thrifty beginnings.

The vast majority of wasted food isn’t made from leftovers — it doesn’t even get round to being cooked. Prepared items sail past their “use by” date; fruit literally petrifies itself in the back of our vast fridges. We constantly buy more than we need and use less than we should. To change things, we have to look at the way we shop. Most of us head for the supermarket, thinking that we are too time-poor for the alternatives but, as convenient as it is, buying everything in one fell swoop is fraught with the danger of wastage.

Impulse buying is one problem — easy to do when so much produce is laid out in front of you. All that fruit and veg in the supermarket can send you into a frenzy of five-portion mania. You buy a week’s worth of virtuous eating and half of it has aged horribly by Friday.

Add to this all the other little “treats” you spy and it doesn’t seem so unlikely that you will join the millions who consign 37 per cent of their purchases to the bin. But there are ways you can reduce the chances of this. You don’t need to deny yourself the odd treat and you don’t even need to be too thrifty.

1. Next time you do a big shop don’t buy anything that won’t keep medium to long term (that’s at least a month). Bulk up on good tinned things — smoked meats and fish, staples such as pasta and rice — then use these as starting points for meals. You can shop for the fresher, more perishable, ingredients daily.

2. If you do need to buy fruit and vegetables weekly, try to follow the local growing seasons as much as possible. The produce will have travelled less far, been in storage shorter and is bound to cost less. And don’t write off frozen veg! Peas picked and frozen in July from a field in Norfolk will still have more goodness than something flown from Kenya.

3. Try to rely less on prime cuts of meat and fish all the time and go for some good slow-cooking options. Making casseroles, hearty soups and stews or pot roasts will make you a more confident cook, and freeze brilliantly.

4. If you are able to start doing smaller daily shops, head for greengrocers, fishmongers and butchers, who are usually happy to get in items you request. The packaging in smaller retailers tends to be less extravagant than the supermarkets, making your shopping even less wasteful.

Emma's Kitchen...

Fridge: Champagne; 1 pumpkin; 4 leeks; 2 lemons; red Leicester; parmesan; tub of cream cheese; butter; processed chicken slices; sundried tomatoes; eggs.

Store cupboard: Tinned tomatoes; garlic; dried mushrooms; tuna; chickpeas; arborio, basmati and brown rice; pasta and macaroni; sweetcorn; potatoes; assortment of herbs and spices, sauces and oils.

... and Tom’s suggestions

Emma has a challenging scenario as she has a family to feed. But she also has some great store cupboard items. If she is fed up with seeing those wonderful, smoky dried mushrooms ending up in a risotto, she could try cooking them with the leeks, pumpkin and chickpeas, to make a great vegetable casserole.

Soak a handful of the mushrooms in about a pint of hot water from the kettle and set them aside. Peel and chop two cloves of garlic and fry them with the leeks in a couple of tablespoons of olive oil. Meanwhile, peel and dice half the pumpkin. Add it to the pot, swiftly followed by the drained chickpeas and chopped tomatoes. Add the stock from the mushrooms, through a strainer to catch any grit. Rinse the mushrooms, then chop them almost to a paste and fold into the stew. Cook until the pumpkin is tender and the juices have thickened slightly. It could take from about 40min to an hour. Season and serve with fresh grated parmesan.

Now back to that pumpkin, which is almost always bigger than you need. Emma could roast any leftover, before peeling it and puréeing. This freezes well and can be used later.

Tinned fish is great to give children omega3. Emma could make a stuffed jacket potato dish by chopping hard-boiled eggs and sundried tomatoes into the tuna.

Red Leicester would be ideal for making macaroni cheese. Simply make the usual white sauce while you boil the pasta. Then, when you fold in the cheese, add a heaped tablespoon of grainy or Dijon mustard, which will not taste strong but will intensify the savoury quality of the dish.

You could enrich it further by grating fresh parmesan — or perhaps a little nutmeg — on to the top before grilling it.

Sacha’s kitchen...

Fridge: Half a pot of taramasalata; 1 avocado; block of cheddar cheese; parmesan; broccoli; chillies; cream cheese; butter; half a bottle of vodka; bottle of white wine; chorizo; pint of milk; 4 eggs.

Store cupboard: Pasta and rice; lentils; 2 cans cannellini beans; 4 cans chopped tomatoes; rye bread; garlic; onions; new potatoes; herbs, spices, saucesand oils.

... and Tom’s suggestions

Sacha is well placed for expanding her repertoire. If she likes pasta but wants to branch out from tomato sauce, she could try broccoli, chilli, garlic and parmesan. While the pasta boils, heat olive oil very gently and fry a clove or two of garlic and one of the chillies. Break the broccoli into small florets and add to the garlic and chillies. Just before the pasta is drained, add a couple of tablespoons of the water to the broccoli mix and take it off the heat. Toss the broccoli and pasta with parmesan and butter.

Another item that catches my eye is the chorizo — it lasts ages and spruces up simple ingredients. Here is a slightly ersatz version of a great Spanish larder dish called gypsy eggs. Dice the chorizo and fry it; use the paprika-rich fat to sweat a couple of deseeded chillies with an onion, then add a tin of tomatoes and cook the sauce until it is ever so slightly jammy. Transfer to a baking dish and preheat the oven to around 250C. Break two eggs per person into the dish and bake until the yolks are only just set. Serve with crusty bread or a pile of the new potatoes.

Lentils are fantastic. Sacha could try a spiced dish such Indian dhal. Pop a handful of lentils per person into a pot and cover with water by about an inch. Bring to a simmer and skim off any froth, then cook until tender. Dice a couple of onions and fry briskly in oil and butter. Add a simple combination of spices: I like cumin and dried ginger. You could also go for coriander seeds or garam masala. Fold the onions and spices into the lentils once fully cooked. Season and, if you have it, garnish with some coriander leaves.

One more thing: dhal will thicken in the fridge overnight. So rather than lose any leftovers, Sacha should keep it and spread over rye bread the next day.

Cupboard Love by Tom Norrington-Davies, £8.99, Hodder & Stoughton

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