Make Caramelized Onion Ice Cubes So You Always Have the Good Stuff on Hand (2024)

So what do you do with frozen cubes of caramelized onion, once they’re part of your freezer stash? Here are a few ideas:

1. Stir into soup or stew

This is perhaps the obvious choice, but French onion soup is a classic for a reason. But don’t stop there: RCOs can boost the flavor of any soup or stew you have on the stove. (Or in the slow cooker! Or in the Instant Pot!) You can even blend RCOs into a creamy sweet and savory puréed vegetable soup.

Cooking for one? Toss a single cube into an oven-proof bowl, add a bit of stock (any kind, however much you want to eat), then warm it in a moderate oven (about 350°F) until it’s hot (microwave works, too). Slide a piece of toast on top and sprinkle on some cheese (Gruyère is choice) and stick it under the boiler or into a toaster oven. You’ve just hacked French onion soup for one in a few minutes flat.

2. Make quick work of a meat sauce

Recipes for sauce made with ground meat frequently start this way: Brown meat, remove meat from pan (requiring a holding vessel you’ll then have to wash at the end of the night), sauté onions and whatever else, return meat to pan. With RCOs in the freezer, you can go straight from browning meat to tossing in a cube of cooked onion—which will be packed with more flavor than the onion you’d spend 5 minutes cooking otherwise—to finishing that sauce.

2A. Or for that matter, any pan sauce

No need to rely on meat: Make a quick pan sauce with RCOs, maybe a little flour, maybe a little wine, and a bit of stock and you have a near-instant pan sauce (or gravy) to pour on a baked potato, a biscuit, or a plate of roasted vegetables.

3. Whip up a mean 15-minute pasta

In This Will Make It Taste Good, Howard has a recipe she calls Anchovy Gateway Spaghetti. She cites it as a quarantine-cooking go-to in her home, something she turns to when she doesn’t feel like cooking. This similar recipe is missing the anchovies, but you could sauté a few (about four fillets) with the garlic before adding pre-cooked onions, Parmesan, and hot noodles. Or leave them out—she says “the onions are so meaty and rich and have a creamy texture all on their own, so they’re great simply tossed with pasta.”

4. Improve instant party dip

Onion dip from a packet: very quick and delicious. Onion dip with your thawed RCOs: very quick and omg so good.

5. Turn up the notch on a can of beans

We’re big fans of warming up a can of beans and calling it dinner. Toss a cube of caramelized onions into the pan and dinner just went from “okay, fine, bean night” to “heck, yeah, it’s bean night!”

6. Add them to eggs

Fold warmed RCOs into an omelet. Whisk them into a frittata. Scatter them over a not-sad scrambled egg dinner. Use them as the base of baked eggs. Spoon a dollop on top of deviled eggs. The possibilities are endless.

7. Grill a cheese sandwich that’ll make you forget about soup

I’m not saying that a grilled cheese sandwich needs anything more than bread and cheese (and mayonnaise), but slather a layer of RCOs on one side of the bread and you’ll forget the side of soup is even there. Take it further with a ground meat patty, veggie burger, or shredded chicken and it’s a melt you won’t soon forget.

8. Layer in a tart

Caramelized onions make a stellar savory tart. You can keep the filling singular with just the onions stirred into a custard, or spread a thin layer on the bottom of the crust, then top with sliced tomatoes (maybe paired with figs), dollop with melty cheese, or scatter with mushrooms or potatoes. Pissaladiere is a classic French-Italian tart that balances sweet caramelized onions with salty anchovies. Or, you could always double down on the onions.

8. Pour out a co*cktail

I may have mentioned a dirty martini above in jest—but listen, if you want to try it, I’d love to hear how it goes. However, should you choose to purée a cube of caramelized onions into the tomatoey base of a bloody mary—a move Howard endorses, in theory at least—you may be on to something.

9. Whisk into a dressing

A spoonful of thawed caramelized onions and a scattering of herbs take a plain vinegar and oil salad dressing to new places. And you’re not limited to leafy greens: Toss an oniony salad dressing with roasted vegetables for a simple and delicious side dish, or even a vegetarian main.

10. Top a pizza

Who needs tomato sauce!? Scatter RCOs across your dough and scatter with blue cheese. Pro-tip: drizzle the finished pie with balsamic vinegar. Or top the caramelized onions with fontina and mushrooms. Prosciutto and mozzarella? Sure. It’s your onion pizza! And it's your onion stash to do with as you please.