Substituting for onions

February 1, 2022 3:00 PM

What can I substitute for onions that will provide the sweetness, bulk, depth, and general infusion of flavor that you get from sauteing onions with various spices? I can't use anything in the onion/allium family: no leeks, shallots, garlic, etc. Also, no mushrooms and not too much celery.

I am aware of asafoetida, but I specifically need a sweet, caramelizing, spice-absorbing ingredient. Just one of many possible examples: if I wanted to make doro wat, which traditionally starts with buckets of chopped onion cooked for an hour. Or a mirepoix-based soup. I'm not looking specifically for onion-free recipes or cuisines, I just want some suggestions on adapting onion-dependent recipes. I'm a decent cook with access to a wide variety of ingredients.

posted by expialidocious to Food & Drink (24 answers total)

Parsnips and celery root/celeriac (and to a less degree carrots) will caramelize over a long cooking period and have a bit of the sort of earthy sweetness to them that I associate with onions.

You may also consider fennel plus a bit of sugar. However, I think fennel isn't FODMAP free (as suggested by your tags), and it's somewhat expensive to use.
posted by saeculorum at 3:02 PM on February 1, 2022 [10 favorites]

Cabbage caramelizes and gets sweet-ish and rich if you cook it hot enough for long enough. It certainly isn't an onion substitute, and it wouldn't get as sweet as onion without some added sugar, but there might be situations where it does what you need.
posted by nebulawindphone at 3:11 PM on February 1, 2022 [11 favorites]

Along with the excellent suggestions above of carrots and cabbage, you might throw in some chopped Jerusalem artichokes (also called sunchokes; it's a tuber, not an artichoke) as well.
posted by heatherlogan at 3:37 PM on February 1, 2022 [2 favorites]

Maybe diced sweet potato?
posted by Lexica at 4:02 PM on February 1, 2022 [1 favorite]

Orange, red or yellow peppers caramelize and hold spices nicely

Also, I’m thinking white, sugar or golden beets.
posted by rw at 4:12 PM on February 1, 2022 [2 favorites]

Cabbage is a good idea for something that's relatively flavor-neutral. I'd also try fennel. I've made plenty of braises starting by slow cooking and lightly caramelizing it.
posted by General Malaise at 4:13 PM on February 1, 2022

D'oh, missed that above. Feel free to move along.
posted by General Malaise at 4:14 PM on February 1, 2022

Another good thing about cabbage is you can slice it to mimic the onion and it will retain toothsomeness like the onion would.
posted by feistycakes at 4:19 PM on February 1, 2022 [3 favorites]

Seconding fennel (if it's actually compliant with you dietary restrictions).
posted by saladin at 4:29 PM on February 1, 2022 [1 favorite]

I would do small-diced bell peppers.
posted by lunasol at 4:40 PM on February 1, 2022 [1 favorite]

I’ve heard diced apple makes a weirdly good substitute for onion in these contexts. Personally I think chard stems work well too.
posted by mismatched at 4:45 PM on February 1, 2022 [4 favorites]

Oh something else that would probably work pretty well is zucchini or yellow squash.
posted by General Malaise at 4:49 PM on February 1, 2022 [1 favorite]

Carrots are a little sweeter than onions, but braise them in chicken broth and butter, or veg. broth and vegan 'butter' and they deepen in flavor. Onions will kind of dissolve more than carrots, so maybe some cabbage for that nice texture.
posted by theora55 at 5:02 PM on February 1, 2022

If it works for your diet restrictions you can make shallot or garlic oil by cooking those ingredients and discarding the solids. (This often works for people with IBS). Combine that with some of the veggies suggested above for texture.
posted by leslies at 5:15 PM on February 1, 2022

Honestly, though, if I was in your situation, I'd be looking at multi-part solutions. You don't need one ingredient or process that brings everything good about onions. You just have to find a way to check all the boxes.

Like, if someone told me to make a FODMAP-friendly version of my beloved onion-heavy chicken paprikash, I'd have some checkboxes in my head: [ ] thickening, [ ] sweetness, [ ] depth, [ ] aroma. And then I'd think "Well, parsnips taste good in European food, and they have good texture and sweetness. Wine has sweetness and depth. I could roast the parsnips too, that's extra depth. And fuck it, for aroma I'll just use asafetida after all..."
posted by nebulawindphone at 5:19 PM on February 1, 2022 [3 favorites]

Radish? Jicama?
posted by eyeball at 5:41 PM on February 1, 2022

I think parsnip would work very well (maybe in combination with a couple of other things). It's a little less sweet than carrot but still caramelizes well. It also has a deeper, more complex flavor than carrot, with a slight hint of spiciness.

You'd probably want to peel it into long, thin strips for maximum surface area exposure while sautéing.
posted by theory at 5:53 PM on February 1, 2022 [1 favorite]

I'm pretty sure the reason European Jewish food has so much caramelized onion in it is because we can't use pancetta-type pork products, which are what the rest of European cuisine generally uses to create a savory base. So - pancetta for the savoriness?

For bulk + sweetness, I agree with finely diced apple.

Another "savoriness" infuser is anchovies that mush and melt into the rest of the stuff.
posted by fingersandtoes at 7:13 PM on February 1, 2022 [3 favorites]

Usually with a low FODMAP diet you can use green onion tops and also chives. Those options and some others are discussed here on the Monash University web site. Monash U actually goes out and tests things to find out how much FODMAP they have rather than guessing.

The FODMAP app from Monash U says regarding "Spring & scallion onion, Green top ONLY":

FODMAPs were not detected in this food. Eat freely and according to appetite.

It says the same thing about chives.

Keep in mind it is IMPORTANT here to use ONLY the green part of the green onions. You must cut off and discard any white or pale portions.

This may not work for you if you have some kind of separate allium allergy or something. But from the strictly FODMAP perspective, green onion tops & chives should be AOK.

Even with that, I probably wouldn't just cook up 10 cups of green onion tops & worf them all down.

But maybe cook up cabbage, parship, fennel, etc as described above and then also include a certain amount of green onion tops (and/or maybe asafetida, garlic-infused oil, & such - those are discussed on the Monash U page linked above) to improve the flavor.

The other flavor I've found that works somewhat similar to onion, in the sense that it's spicy when raw but cooks out have a more meaty and complex flavor that is really nice, is ginger.

Again I wouldn't just cook 10 cups of ginger but it may be helpful as an additive to some other things to add some nice flavor. However, experiment first - you may not like it at all.

Ginger is also 100% FODMAP friendly with "no FODMAP detected" from the Monash U app.
posted by flug at 8:12 PM on February 1, 2022 [4 favorites]

Asafetida, also called hing. Used in Indian cooking to impart an oniony, garlicky flavor without using onions or garlic (or to supplement them). You could combine it with cabbage or other veggies mentioned above, to get the bulk of the onion as well as the taste. It's pretty pungent - a couple of pinches as you cook will do.
posted by infodiva at 11:14 PM on February 1, 2022 [2 favorites]

Smoked bacon, pancetta or pork belly
posted by mani at 2:57 AM on February 2, 2022

Response by poster: These answers are great, thanks. Unfortunately pork products are a no-go for exactly the reason fingersandtoes mentioned. We’d like to stick to vegetables, herbs, or spices for kosher purposes.

Also, we are big fans of the Monash app and have narrowed down the possible fodmap triggers to fructans, GOS, and mannitol.
posted by expialidocious at 8:37 AM on February 2, 2022

Actually, I think more examples would be good, because there might be different solutions for different recipes. I think for the doro wat, grated carrot and parsnip and a hint of hing/asafoetida, will work very well. For shakshuka, I'd use peppers and a bit of eggplant, not too much.
Also fresh herbs can play an important role in this context. Carrot is sweeter than onion, so freshly chopped parsley or mint on top of a serving can add a bit of peppery contrast to a dish. Coriander/cilantro can add sweetness. Watercress is delicious on a lot of things and again has a hint of pepperiness along with sweetness.
posted by mumimor at 8:59 AM on February 2, 2022 [1 favorite]

I was looking for a substitute for onions for a tagine this weekend, as roasting them in the oven gives me terrible stomach ache. I used sweet potatoes. This helped me work out what might be best for my recipe, maybe it’ll help you too?
posted by tinwhiskers at 10:46 AM on February 2, 2022