Leftovers–Make A Plan to Use Them Up

Welcome to the fourth post in my series about reducing food waste. In post one, I defined the scope of the food waste problem. In post two, I talked about mindfulness in food shopping and developing a meal planning practice in small increments. Post three offers some tips for planning meals. In this post, I will tackle leftovers, both the extra food from meals and the stuff that might be languishing in your fridge or cupboards.

Leftovers have been a topic of discussion in cookbooks and food media since at least the turn of the 20th century when, as documented by Laura Shapiro in Perfection Salad, “precise dispersal of leftovers” became a focus of the budding field of scientific cookery. She provides an example from an 1895 edition of Household News:

“…on Friday you have sauce tartar; yolk of one egg will be quite sufficient, and for dinner mayonnaise will take two, and sauce hollandaise two more, so you will probably have five whites for your sponge gems on Saturday…You will probably have more chopped meat than you want for meat cakes, especially if you add also the bits of lean meat from bones and sirloin steaks. This can be used for smothered beef Sunday morning. The bones must be placed at once in the soup kettle, covered with cold water, and cooked slowly for four hours to make clear soup for Sunday dinner, and macaroni soup for Monday.”

Fast forward a half-century and you’ll see a continued emphasis on the notion of using up leftovers. The Culinary Arts Institute Encyclopedic Cookbook, published in 1959, offers 300 recipes for leftovers, including these hors d’oeuvres:

Excerpt from a mid-century cookbook.

(Number 3 is particularly intriguing. I’m not sure about the aesthetic value of sticking bacon-wrapped peanut butter into an eggplant, but it was a different time. Points for creativity I guess.)

I would never recommend anything as exacting as the first example, nor as unappetizing as,  well, all of it, but the general idea of planning for leftovers is a good one.  

Leftovers are hard to avoid, even with the best meal planning. Some recipes make more than you anticipate or some people may eat less than you expected. The same goes with shopping–no matter how carefully you plan, it is easy to end up with extra food. The key to avoiding food waste is to have ideas for leftovers when you make your meal plan. (But maybe not the bacon skewers in eggplant. Or the smothered beef on Sunday morning.) 

So, what can you do with leftovers? I will provide some ideas and inspiration here but, before we get started, let me say that a good deal of food waste can be avoided with proper storage. You can read more about that in Storing Foods to Avoid Waste.   

Dealing with Leftovers

Planning for leftovers means having a few standard recipes and preservation techniques in mind so when you are faced with leftover food, you can make the most of it. 

My first recommendation, as stated above, is to factor leftovers into your meal plan. For example, if you’re serving roast beef one night, you can plan to use leftovers in sandwiches or served with gravy over egg noodles the day after. If you buy a rotisserie chicken, you can plan to serve leftover chicken in fajitas or a stir-fry the next day. 

When you make your shopping list, you should also have some general ideas in mind for any extras you might have at the end of the week. If you buy a fresh herb for a dish, plan to freeze the excess or use it in a sauce. Fruit that doesn’t get eaten can be frozen, used for smoothies, or made into sauces, like applesauce or a berry sauce for drizzling over pancakes, waffles, oatmeal, or ice cream. Keeping these ideas in your back pocket makes it more likely you’ll use what’s left behind before it starts to go bad.  

My second piece of advice: when you structure your meal plan, aim to use up the more fragile or date-sensitive foods earlier. For example, if I buy romaine hearts, I make a plan to use them before they go bad, maybe in a traditional garden salad one day, a Caesar salad another day, and as a garnish for burgers or sandwiches. Meanwhile, the carrots I also bought for the salad can wait a few days, being served later in the week with other raw vegetables and some ranch dressing. Similarly, if I buy fresh chicken or beef, I aim to cook it early in the week rather than let it sit in the fridge for too long.* 

Lastly, in your recipe roster, include some “use it up” recipes designed to use any bits and bobs left behind: sauces like pico de gallo or tzatziki, or sides like fried rice or noodle dishes that can incorporate any mix of vegetables, like mushrooms, green beans, carrots, peppers, or broccoli.

Beyond this general advice, here are some other thoughts and ideas on how to use leftovers. 

Leftover Meals 

If you have leftovers from a prepared meal, can someone take them for lunch the next day? Or have them for breakfast? We sometimes have leftover potatoes, cooked in one form or another. Pan fried, they make a great addition to a weekend breakfast. You can even reheat leftover frozen fries that didn’t get eaten, but maybe for lunch because they do tend to be a bit greasy. 

Can you use leftovers as a side dish for the next night’s meal? For example, a vegetable stir-fry? Or plain rice? If there’s not enough for a side dish for everyone, add another small side and let everyone have a bit of each. If you have leftover rice or noodles, fry them with some vegetables for a quick fried rice. Or just reuse cooked rice as its own side, perhaps with a dash of soy sauce for flavour. (But reheat it thoroughly. See Use It Up: Cooked Rice for more information.)

Can your meal or components of it be frozen? I talk more about freezing below, but starches like rice can be frozen, as can soups and sauces like bolognese, meat braises, or curries.

Finally, if you have a lot left, make notes on the recipe to cut back the quantity so you have less food left over next time. 


If they can freeze it at the grocery store, you can probably do it at home. It took me forever to realize this in the case of some foods, like pineapple. If a pineapple got past its prime, I used to scramble to use it all up in a smoothie or, if I was feeling really ambitious, a pineapple upside down cake. (That was, admittedly, very rare.) But then I thought: they sell frozen pineapple at the store, so I can do that too. Now I cube pineapple, freeze it in individual pieces on a cookie sheet lined with parchment, and once it’s frozen solid, transfer it to a freezer bag. Same with mango, peaches, and berries that are a little soft but not yet mouldy. All of this fruit is great for use in smoothies, fruit sauces, and jam. 

If you have limited freezer space, freezing may be a little harder to do but leftover fruit is likely to be in a very small amount, so it’s worth trying, if you can. If you don’t want to freeze in cubes, try blending or food processing the fruit and freezing it as a puree you can use in smoothies. You can use freezer bags and freeze flat to stack and make storage a little easier. 

You can also freeze soups, sauces, curries, and meat that has been braised in sauce, as noted above. Try freezing meal-sized portions in flat plastic food containers. You can keep them in the containers or, if you don’t have space for all that bulk, transfer the frozen blocks to freezer bags and squeeze the air out.

Blanch hardy greens like kale and freeze in small bunches to toss into sauces or a green smoothie. Spinach is a little less hardy but can still be blanched and frozen, like you see in the grocery store. 

Leftover canned or cooked beans can be frozen for use later in dishes like chili, stew, or soup. And, if you opened a can of chipotle or other spicy peppers for your chili, you can freeze those in small portions and use them whenever you need to add a little heat to a dish.

If you have a large quantity of rice leftover, you can freeze it in freezer bags too. (See Use It Up: Cooked Rice for information on how to do this safely.)

One final and very important point about freezing: be sure to label everything. Get yourself a Sharpie and write what the item is and a date so you can avoid bottom-of-the-freezer guessing games months later. You think you’ll remember but, trust me, in most cases, you won’t. 

Leftover Ingredients

So you bought one too many limes for your pad thai dish. What now? This is where it’s beneficial to have a plan for excess ingredients. If you can’t freeze it, you’ll need other ideas. 

Turning back to that extra lime, it can go into a fresh pico de gallo to serve with the chicken fajitas (the ones made with leftover rotisserie chicken.) If you have extra lemons, yes, you can make lemonade, or plan to make a salad dressing or a sauce like tzatziki. Or use lemon or lime wedges to flavour water. 

Here are some other ideas to get your creative juices flowing:

  • As mentioned above, you can use leftover cooked meat in stir-fries, fajitas or tacos, or sandwiches. It can also be served with gravy on rice or egg noodles, or added to a tomato-based pasta sauce. Or you can make a quick fried rice with small amounts of leftover rice and cooked green beans or other vegetables.  
  • Extra cooked but unsauced pasta can go into a pasta salad. You can whip up your own dressing with your extra lemons or use a bottled sauce you already have on hand. Add some raw vegetables, olives, or feta cheese–lots of possibilities here. 
  • You can roast some leftover uncooked vegetables, like peppers and tomatoes. Use them in omelettes, pasta sauces, fajitas, or wraps. 
  • Plan for a soup making weekend to use up celery, carrots, onions, mushrooms, or potatoes, depending on the recipe. If you cooked any kind of bone-in meat, you can use the bone for soup too.
  • Cook and puree apples to make applesauce. You can do the same with pears. Apples are also easy to incorporate into desserts like apple crisp or pie, if you have skill in that particular area. (I do not, so pies are never on my list of “use it up” ideas.)
  • Other types of baking are good for using up pantry ingredients and some fruits or vegetables. Lemon or zucchini loaf comes to mind, as do carrot muffins. Use up extra pecans, walnuts, or dried fruit in loaves or muffins. And oatmeal cookies can handle lots of additions, including the aforementioned dried fruit and nuts, coconut, and, of course, chocolate chips. 
  • Smoothies are the ultimate fridge cleaner. You can combine just about any fruit and many vegetables and juices in a smoothie. I tend to make mine non-dairy, but you can add yogurt or milk if you need to use those up. Or, if you have extra coconut milk from a recently made entrée, toss that in. Really, anything goes with smoothies. 

Those are just some general ideas to get you thinking about how to use leftovers. You can find more ideas online and by clicking the Use It Up tag in the sidebar. 

* I realize it sounds exhausting to think like this, but once you’ve gotten into the habit of meal planning, it will become second nature. 

I am writing this blog series in the knowledge that many families have financial constraints that limit their food choices and for whom food waste is not an option. If you would like to make a donation to help people living with food insecurity, here are a couple of organizations I have supported: Food Banks Canada and Breakfast Club of Canada. Your local food bank would also welcome donations of food or cash.

Illustration 140584187 © Esfir Dzhi | Dreamstime.com


Culinary Arts Institute of Chicago (1959) The Culinary Arts Institute Encycolpedic Cookbook. Revised ed., Ruth Berlolzheimer, Ed., Chicago: Book Production Industries, p. 277.

Shaprio, Laura. (1986) Perfection Salad: Women and Cooking at the Turn of the Century. New York: The Modern Library. p. 85.

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