Leftovers. Sadsacks of the kitchen. Wallflowers at the culinary dance. Plangent carrots, shriveled apples, woeful noodles, cucumbers d’un certain age. Overlooked, passed over. Growing ever more mournful and fuzzy. Left long enough, they begin to harbor micro-organisms: Aspergillus niger, Botrytis cinerea, Penicillium digitatum, Penicillium expansum, Penicillium italicum, Rhizopus stolonifer…and more… They can extrude unpleasant odors—you might catch a whiff of stinky cheese (produced by butyric acid). Or perhaps you get a hint of rotten egg smell which comes from hydrogen sulfide (an odor so potent that human beings can detect it at .02 parts per million.) What was once desirable and appetizing is transformed into a nasty item fit for nothing but disposal.

Food waste is a worldwide problem. In July 2008, Gordon Brown, the prime minister of Britain, decided the issue was important enough to add it to his brief. He urged families to stop squandering food after a study revealed that they were throwing away groceries worth £10 billion a year. He blamed these wasteful practices for contributing to soaring prices. The David Suzuki Foundation reported that close to half of all food produced globally is discarded as it is processed, transported, sold in supermarkets or after arriving in someone’s kitchen. The average Toronto family throws out about ¾ of a kilo of food a day. Every year, the city spends $10 million getting rid of the uneaten groceries that aren’t composted. When people toss food, all the resources to grow, ship and produce it are wasted too, including massive volumes of water. In the US, the water loss from food waste amounts to 40 trillion litres down the drain annually. Making food requires carbon too; if we stopped wasting the food that we could have eaten, it would be equivalent to taking 1 out of 5 cars off the road.

For years, I’ve been passionate about not wasting food. I hate to throw it out. Doing so strikes me as akin to spurning a well-intentioned gift. I don’t how this attitude became so firmly lodged in my psyche. Was it because I was born in China? Even though I arrived in Canada when I was nine months old, maybe it left its mark. My mother used to tell me that in China, people believed you had to eat every last grain of rice in your bowl—otherwise the Gods would be angry.

Calvin Trillin once wrote that his mother served his family nothing but leftovers and the original meal was never found. In the same vein, is a comment I found on I found on BBC website. A man recalled how his father would mash leftover potatoes with flour to make scones. Then he would mash leftover scones with leftover peas to make green potato scones. Mercifully the leftover green potato scones were allowed to die a natural death. This is leftovers as penance. I’m not that extreme. I don’t want the people I am cooking for to feel duty-bound to eat what was left over. I want them to eat it because it tastes good and is enjoyable. That’s a point of pride with me—that challenge. It’s not hard to make a good meal out of fresh ingredients, but if you make one out of leftovers, you’ve earned your chops as a truly creative chef.

Here then is my collected leftover lore—the zen of leftovers. You’ve got the theory, now here’s the practice.

A

Apples

In western culture, apples are considered highly desirable. That’s why a beloved child is sometimes referred to as an apple in someone’s eye. It may also be why in Christian tradition, the fruit with which Eve tempted Adam was an apple. And it’s probably also why clever marketers called a computer an apple thereby grafting some of its mouthwatering and delicious qualities onto a machine. There are thousands of varieties of apples and thousands of recipes: Apfel Strudel, torta de mele, tarte aux pommes, appelkaka, yabluchnyk, apple pie, appeltaart, tarta de manzana, omenalimppu… Everybody loves apples. But it’s not apparently enough to keep them from being wasted. Kept in a cool dry place, apples can be stored for months, but according to The Food We Waste, Britons toss out over 4 million apples a day. It’s probably not so different elsewhere.
If you have one apple that’s getting a little long in the tooth, here’s good recipe for a Pear or Apple Cakeou can also incorporate apples into Apple Crisp, Apple Pie, or Apple Sauce. If you end up with too much apple sauce, there are recipes for apple sauce muffins and cakes. You can also freeze it.

B

Bananas

Bananas are the world’s most popular fruit. They originated in Malaysia and then were spread around the tropics. The type we eat is called the Cavendish. It is actually under siege from a fungus called Panama disease that has wiped out plantations in Indonesia and Malaysia. It’s not the first time this has happened to bananas. In the early sixties, we used to eat a variety of banana called the Gros Michel; a fungus completely wiped it out.
Now we eat about 70 million metric tonnes of the fruit every year, but we also throw them out. The Food We Waste says that in Britain, 75,000 tonnes of bananas are discarded every year. That’s because after they get black spots on them, they’re not so appetizing. They are, however, perfect for baking! See Banana Bread or Banana Orange Muffins.

Butter

You can keep butter for several months in a refrigerator if it is tightly wrapped up and not exposed to air or light. (Between the 11th and 14th centuries the Irish used to pack butter into barrels and bury them in peat bogs for years. This butter remained edible as it aged because of the cool, airless, and antiseptic environment of the bog. Buried butter is still a common archaeological find in Ireland and to this day, while presumably not a culinary delight, is not rotten either.) I save the foil wrapping from butter in the freezer. When I need to grease a baking sheet, a loaf pan, or a muffin tin, I use these pieces of foil. They usually have enough good butter for the purpose.

Bread

Bread has been a staple food in Europe and the Middle East for thousands of years. It was so important that the Lord’s Prayer asks, “Give us this day our daily bread.” But now it is often wasted. In Britain, 7 million slices of bread end up in the garbage every day. Slices and loaves of bread comprise 10% of the total food waste there. It is astonishing to me, since bread is one of the easiest of foods to transform into delicious leftovers. Slightly stale bread can be used in French Toast or Sausage Strata or Bread Pudding.
If you have just a small amount of bread, you can dry it and grind it up with a food processor to make bread crumbs. I usually save heels of bread until I have a cup or two and then put them into the processor. Bread crumbs have many many uses. See Cod in Bread Crumbs, Hamburgers, Stuffed Mushrooms, or Easy Microwave Macaroni and Cheese.

Cheese

Cheese first appeared around 7000 BC—when human beings began to breed livestock. It arose as a way of preserving the nutritional value in milk for longer periods of time. It was, in other words, an early way of avoiding the problem of leftovers! Since cheese lasts quite well, you may not have a problem with leftovers. But if you do have various small bits of cheese that are too dry to use in sandwiches, you can make a Quiche Lorraine or a Cauliflower Cheese Sauce out of them. Crumbs of blue cheese can be made into a delicious Salad Dressing or sprinkled into a Spinach Apple Salad.