More Vegetarian Recipes
Caramelised Onions
Ingredients
- 1kg brown onions, peeled
- 2 tbsp olive oil
- 2 tbsp salted butter
- 1 large pinch sea salt flakes
- 1 tbsp balsamic vinegar
Instructions
- Melt the olive oil and butter together in a large, heavy-based pot over low heat (about 2–3 minutes).
- Thinly slice the onions using a mandolin for even slices. Add the onions to the pot, sprinkle with salt, and stir to coat in the oil and butter.
- Cook over low heat for 40–50 minutes, stirring every 10 minutes, until the onions are golden brown and very soft.
- Add the balsamic vinegar and cook for a further 10–15 minutes, stirring occasionally, until the onions are dark brown, gooey, and sweet.
Notes
- Don’t be tempted to turn the heat up – slow cooking is what gives the onions their jammy texture and rich flavour.
- They’ll keep in the fridge for up to a week in an airtight container, or you can freeze them in portions for future use.
- Perfect for topping steak, swirling through mashed potatoes, or adding to your favourite tart or quiche.
- If the onions start to stick or catch on the bottom of the pan at any point, add a splash of water to loosen them and prevent burning – this won’t affect the flavour, and it helps keep them cooking evenly.
Nutrition Information:
Yield:
12Serving Size:
1Amount Per Serving: Calories: 75Total Fat: 4gSaturated Fat: 2gTrans Fat: 0gUnsaturated Fat: 3gCholesterol: 5mgSodium: 29mgCarbohydrates: 9gFiber: 1gSugar: 4gProtein: 1g
Please note, this nutrition information is to be used as a guide only. Nutrition information isn’t always accurate.
Want to know when I share a new recipe? Subscribe today!
How to Make Caramelised Onions
This Is Not a Quick Recipe, soz
Once upon a time I believed that browned onions were caramelised. I’d chuck them in a pan, let them brown a bit, and assume that was good enough. But no. Proper caramelised onions? They’re jammy, gooey, golden and glossy. Oh so sweet, too. And truthfully, it took me ages to get them right. The night I finally nailed it, I was making a Crottin de Chavignol tart – goat’s cheese and caramelised onion, baked into golden puff pastry. And honestly? It was the best tart I’d ever made. Once I had the onions down, they ended up in everything. Pie, onion gravy, a cheeky addition to toasties and grilled cheese. I even made a caramelised onion pasta once, and wow – total game changer.
The trick, as I learned the hard way, is to get the onions sliced as evenly as possible. This is where the mandolin comes in handy – if you don’t have one, they’re about $10 and will saved you a lot of time. Just watch your fingers – I say that from experience. I once managed to slice deep into my finger even though I thought I was being careful!! Anyway, the onions need to be thin, as thin as you can get them, for that proper slow cook where everything softens and melts together. Not rushed, not browned, but properly caramelised. Deeply savoury-sweet and soft, like a good chutney.
And here’s the part I didn’t expect: you actually don’t need a tonne of oil or butter. A little goes a long way. Too much, and you’ll end up with a greasy mess that never quite sticks together. I use just enough to get things started, and if I do go overboard, I soak up the excess with a bit of paper towel. The magic really happens when you stir in a splash of balsamic vinegar and a generous pinch of sea salt flakes at the end. Don’t skip that bit – the vinegar cuts through the sweetness and adds a lovely tangy depth, while the salt wakes everything up.
The Tart That Changed Everything
So let’s talk about that tart for a second – I still dream about it. I’d been craving something indulgent and cheesy and inspired by my time in Paris many many years ago, to serve to my girlies – I wanted something a little fancy, but comforting too. That’s when I decided to try pairing caramelised onions with Crottin de Chavignol – a soft, slightly tangy goat’s cheese that melts into everything and holds its shape just enough to stay rich and creamy. The pastry turned out beautifully crisp and golden, the cheese all oozy and sharp, but the star of the show was the onions.
Those onions, glossy and sweet, made the whole thing taste like I’d spent hours in a Parisian kitchen, not twenty minutes faffing about in mine while sipping a green tea and cursing the oven for being temperamental. They added richness, but also contrast. Sweetness to balance the tang of the cheese, a depth of flavour that made it feel like more than just a tart. It was the kind of thing you want to eat slowly, with a glass of wine, and then go back for seconds anyway.
Since then, I’ve never looked back. If I’m having people over, I’ll often make a version of that tart – sometimes with feta, or a softer goats cheese paired with thyme. But always with the onions. Always. They’ve become one of those staples in my kitchen – the kind of thing I’ll make in bulk and keep in the fridge, ready to stir through eggs or dollop onto pizza. Once you get them right, they’re kind of addictive.
Tips for Getting it Right
If you’re giving caramelised onions a go, don’t rush it – this isn’t a ten-minute job. I mean, you can cheat with a bit of brown sugar if you’re desperate, but it’s not the same. You want slow and steady, low heat, patience, and stirring occasionally. I like to set myself up with a cup of tea or put on a podcast – anything to stop me from trying to speed things up – the process is half the joy!
It helps to use a wide pan so the onions have space to do their thing. Crowding them just means steaming instead of caramelising, and that’s not the vibe we’re going for. And don’t forget to keep an an eye on the colour – you want that deep, golden brown, not burnt, not dry, and they should look almost like jam. And don’t forget the final splash of balsamic! It sounds like a fancy touch, but it genuinely makes all the difference.
Also, just accept that it’ll take time to find your groove. I made a mess plenty of times before I got it right. Too much oil, too much heat, not enough patience. But once you do get it, it’s the kind of thing you’ll want to add to everything. And fair warning: people will ask you for the recipe. Every time.
Ingredients Breakdown
Onions are, of course, the foundation. I go for brown onions mostly, though red ones will give you a bit more sweetness and a slightly different depth. Whatever you choose, make sure they’re fresh and firm – the older they are, the more unpredictable the flavour can be. You want to slice them thinly, as evenly as possible, and that’s where a mandolin helps – just mind your fingers.
Butter and olive oil are the fat duo here. You don’t need much, just enough to coat the onions and get the process started. I find a mix of both gives you the richness of butter and the stability of oil without it becoming too greasy. If you do accidentally go overboard, a quick dab with paper towel works wonders. It’s about finding that balance where the onions gently fry and soften without drowning.
The final flourish comes from sea salt flakes and balsamic vinegar. The salt brings everything together, lifting the sweetness and balancing the overall flavour. I always add mine at the end, once the onions have done their thing. Balsamic vinegar is the secret weapon here – just a splash, right at the finish. It deepens the flavour, adds brightness, and stops the onions from becoming cloying. Without it, they just don’t hit the same notes.
