There are two approaches to cooking for one person. The first is to make a big pot of something (soup, stew, rice) and either freeze most of it or eat it throughout the week. This is, of course, an excellent strategy. But sometimes, for the sake of variety and specific cravings, an individual portion is required, such as an omelet, or a salad, or any variety of things that can be done with a chicken breast or a salmon fillet. This is where the onion becomes a challenge and the shallot a hero.
Red, yellow, and white onions are sold in a variety of sizes, but most often they are large or even extra-large. Softball sized, at least. And if a single diner wants to include a bit of onion in her evening meal, it can prove a challenge to find an onion small enough for a single portion. Of course, she can use a slice or two and wrap the rest up a plastic bag and stick in the fridge, but that creates another cascade of issues around continuing to use up the onion throughout the week. Sometimes, the single cook just wants a little onion and to leave it at that. Enter the shallot.
Shallots are small, often no bigger than an elongated golfball and they make a perfect, single portion onion. Their beauty is in their compactness, with no lingering unused portions to manage with though out the week. It's always good to have a few shallots in the single person's kitchen as they store almost as well as an onion and therefore can be easily kept on hand.
As far as taste goes, shallots are reported to be milder and sweeter than a regular onion and for the most part, this is true. This is why a regular onion should be used for a stew or soup where it can offer up enough robustness and flavor to withstand the longer cooking times. A single cook will most likely make up a larger batch of these kinds of dishes (has anyone ever made a single serving of soup from scratch?) and easily use up the whole onion.
The shallot is good for making a vinaigrette, or for sautéing gently as a base for an omelet filling or fritatta. It roasts up nicely with root vegetables and goes well with asparagus, peas and other spring vegetables. It can be used raw, although it isn't always as mild as reported. If you do encounter a strong shallot that you plan on serving raw, I recommend chopping or slicing it and leaving it to sit in some vinegar for at least 10 minutes, maybe even 1/2 hour. This will pickle it slightly and tame some of the strong flavors.
Another mild onion that conveniently comes in small portions is the green onion or scallion. Often, this is this is the onion to use raw, although green onion does work well in a stir fry or other quick cooking dishes. Equally convenient, especially if you have it growing in your herb patch, are chives which are the mildest of the alliums and can be snipped into dishes as a final flourish.
Related: What's the Deal with Shallots?
(Image: Dana Velden)
TW Salt Mill by Wil...

I coursely chop an entire onion, use what I want, and freeze the rest. Frozen chopped onion is easier to dice when I need it again.
The problem is that shallots here cost several times what an onion costs. I just use what I need of an onion and put the rest in a container for later. We use a lot of onions so it doesn't take much time for me to use up the saved onion.
I'm with Ellabee, onions freeze beautifully and shallots are freaking expensive! Onions are $1 a pound or less and shallots are $4/lb on sale. Not to mention half of the time I buy them they end up being old because they don't turn over as quickly as onions in the store. I bought a canister of freeze dried shallots off of amazon and love them, especially tasty sauteed with green beans. Now if they would just sell a large-dice freeze dried shallot and I'd be all set :)
I find the onions sold in 3 or 5 lb bags are much smaller than the onions sold per pound. One of those onions is perfect for single serving cooking.
Informative article. I had to chuckle at the vinegar tip - I choose them for their bite. 'Course I grew up on my grandmother's cooking & a thick slice of raw onion on the side accompanied nearly every meal. They do freeze well. I dice some & slice some & just grab what I need on busy nights. I buy them by the bag, caramelize them, then frieeze them as well.
*freeze*
Yup. Shallots or the smaller onions in the mesh bags for me- at the stores I go to they tend to segregate the bags with the big onions and the bags with the small onions to opposite ends of the produce island. Generally you have a choice of white or yellow, sometimes red too, seasonally.
Yeah, of all the cooking-for-one issues I've had, using up an onion has never been one of them. But then, I love onions, and often what I didn't use at night I'd polish off in the morning with eggs or greens.
But shallots are delicious, too. :)
...one of the shallots in the picture made me giggle...