I'm not sure there's ever been a wiser lyric penned than this one: You've got to know when to hold 'em, know when to fold 'em, know when to walk away, know when to run. It's great advice for so many things in life, cooking included. That's because part of being a good cook is knowing when to go all in, when to cut your losses, and when to throw it all in the trash and order delivery. It also helps to know when it's okay to take a shortcut.
This vegetable stock is exactly that—an acceptable shortcut. I'm a big believer in using the best stock whenever possible, whether chicken, fish, or vegetable, but I also know that sometimes I'm faced with limitations that simply don't allow for the ultimate versions of those things. I may have little time to shop and cook a complicated stock, for example, or I may want to keep things vegetarian or just as light-tasting as possible—without resorting to the total blandness of water. Those kinds of constraints rule out most options, especially since store-bought chicken stock is one of the only non-homemade ones I'm willing to use. (You may notice that we've never recommended a favorite brand of store-bought vegetable stock. That's not an oversight: It's because we've never found one that tastes any good.)
Now, if you have the time to gather things like dried mushrooms and kombu, you can make a really great vegetable stock like this one, which will add a lot more depth and flavor to whatever you're cooking. But remember, the idea here is that we don't always have the time. That's okay, because an easy and perfectly good vegetable stock is just minutes away.
All you need are some aromatic vegetables and water. At the very least, you'll want to use carrots, onions, and garlic. Celery helps, as do fresh herbs, like parsley and thyme, and dried ones, like a bay leaf. Anything else that doesn't have too particular of a flavor can go in, too. Got fennel bulb on hand, or leeks? Use them. I know some folks like to throw any and all vegetable scraps into their stocks, but I tend to steer clear of certain kinds—like sulfurous brassicas (broccoli, cabbage, Brussels sprouts), since they can give the stock a...shall we say...gassy quality.
Just wash 'em, peel 'em, cut 'em up, and throw them all into a pot with enough water to cover, if not more, then simmer it for at least 20 minutes to get some flavor out of the vegetables. If you get the stock going first, you can prep everything else you're cooking in those 20 or so minutes and be ready to rock right after that.
Truth is, there's not even really much of a recipe here, though I've written one up anyway. There's no point in worrying about the perfect ratio of vegetables to water, or an exact cooking time. The bottom line is that if you simmer aromatic vegetables in a pot of water for even a short time, you'll have a very basic but tasty stock with very, very little effort. It sure as hell beats water and store-bought vegetable stock, which are about the only two things that would trump it in terms of speed and ease.
With a quick trick like this up your sleeve, you'll always have time to walk away, no need to run.