When you're cooking for two, it's important to decide how you feel about eating leftovers. People have very different tolerances for pre-cooked food. I know a woman whose husband refuses to eat anything that’s not cooked fresh; I try not to think what happens to the rest of all the roasts she cooks. On the other hand, I’ve known people who will happily eat the same batch of soup or chili for an entire week. Chances are you fall somewhere in between.
I personally don’t like to eat the exact same thing for dinner two nights in a row or even twice in the same week. (And for me, serving roast pork with mashed potatoes and peas one night and roasted cauliflower and salad the next counts as the same thing.) However, in some cases I don’t mind dinner leftovers for lunches. And if a dish can be successfully frozen, I’ll often make extra, portion it out and freeze it for a meal several weeks down the road. But there are some dishes I just don’t like reheated, period, such as fish, shellfish or macaroni and cheese. That’s what I mean by being honest about your leftover tolerance. If you really don’t like leftovers, don’t kid yourself that you’ll eat them. You’ll just end up wasting food.
Another Type of LeftoversLeftovers aren't necessarily extra servings of an entire dish; they can be extra amounts of ingredients you'll use in different meals. Even though I'm not a fan of eating the exact same thing two nights running, I do incorporate this second type of leftovers quite often in my meals. I'll cook extra rice one night, and use it in stuffed peppers later in the week, or cook a large steak and save half of it for tacos or steak sandwiches later. We almost always buy a pound of mushrooms at a time and cook them all; then we use them throughout the week in different dishes. If you do this kind of thing, I think it's best not to season the ingredient heavily – if you’ve rubbed cumin and chili powder on your roasted chicken, it’s going to limit what you can do with the rest of it.
Many people are used to coming up with two or three ways to use up a large chunk of meat – say beef or pork or a whole chicken. For me, that’s easy (although I rarely cook a whole chicken). What’s much more difficult is finding ways to use up vegetables, especially large vegetables like cabbage or cauliflower or those you buy in bulk. When all you need for tonight is two cups of shredded cabbage, you need to find ways to use the rest of the head. If you're using two carrots for dinner but you have to buy a pound, you should start thinking about ways to use the rest of them.
Universal DonorsThe best way I've found to make sure I use up this second kind of leftover food is to keep a running list in my head of dishes I call "universal donors" – that is, dishes that can be made with a variety of meats or vegetables. For instance, I make a spicy broccoli dish that goes well with cooked beef, pork, or chicken. Tacos, enchiladas and hash are other universal donors on my list. An ideal universal donor dish can be altered both with different meats and with different vegetables like this fried rice.
Starting your own list of universal donor dishes is easy. Whenever you're cooking a new (or old) recipe, think about possible substitutions that would taste good and fit in with the dish. Pork instead of beef? Asparagus instead of peas? Of course not every dish can be altered successfully, but with a little ingenuity, you'll find yourself with culinary options you never knew you had.