As the holiday season progresses, we renew our acquaintance with office potlucks, family parties, and the like, as well as a common feature of those events, the veggie tray.

Ah, yes, veggie trays. They’re the tool of choice for those folks who were tasked with bringing a dish but were too scared or too time-stressed to make something. Plus, you get points for providing something vaguely healthy. Go to the store and either buy the trays ready-made or get the constituent vegetables needed to create them — what could be easier?

It’s a great plan, except for this: 90% of the tray’s contents — typically carrots, celery, some green onions, cherry tomatoes, radishes, broccoli, and cauliflower — go untouched. So at the end of the day, somebody has to lug it all home or throw it out. Ugh.

But here’s the secret: If you’re looking to do some soup stock, leftover veggie trays are your friends.

Think about it: In even the simplest veggie tray, you’ve already got at least two-thirds of the Holy Trinity of French flavorings, carrots and celery, in copious amounts. (If you’re lucky, you have some chopped onion as well to complete the threesome; if not, well, you have some onions at home, don’t you? Don’t you?) The fancier trays have even more stock-worthy things, like cherry tomatoes, that you can use — though I’d leave out the broccoli if I were you, unless you plan to make cream of broccoli soup. (That’s OK; if you’re not going to make soup out of your broccoli, just set it aside for a bit and then blanch it in some of that stock you just made. You can then freeze it for later or eat it as a side dish.)

Even better: The contents of veggie trays are already cut up for you in the ideal size for stock making. No chopping needed!

So the next time you’re cleaning up after an office party, graduation party, or some other such function and you notice that nobody’s nabbed the veggie tray yet, grab that sucker with both hands and take it home, and thank whoever was thoughtful enough to bring you your very own stock preparation kit.