I’m no stranger to onion jam. A sweet-sticky condiment of slow-cooked onions, it’s typically served with burgers in Western restaurants. In Asia, it’s sometimes just called “caramelised onions”. Is it nice? Yes, but nothing to get excited about.
Until I ate a version made by a friend in Singapore, using her personal recipe.
Served on plain buttered sourdough, there was a dark molasses-y sweetness, a gentle vinegary tartness, and a savoury, deeply concentrated onion flavour that I had never experienced in commercial versions.
So this was what properly made onion jam tasted like. Grown-up. SPECTACULAR.
How can boring old fried onions taste so good, you might wonder?
Oi. Please don’t insult my good friend onion jam. Onion jam is NOT the same as as “fried onions”, okay? Onion jam is the delectable result of a painstaking, long-drawn-out labour of love that involves two key processes.
One, the Maillard reaction. A chemical process that takes place between amino acids and the sugar in the onions when cooking at high heats, the Maillard reaction is the reason that onions become brown.
Two, caramelisation. This means water gets removed and the sugar breaks down, resulting in that complex, meltingly sweet flavour that makes onion jam so irresistible.
Obviously there was only one thing to do. I bugged my friend for the recipe and she kindly obliged. It does come with a warning …
You need Buddha-level patience. Depending on the volume you make, your onion jam may take up to 2 hours to cook. Not passive cooking time, mind you, where you can go Insta-scrolling while the jam bubbles on the stove.
We’re talking about two hours of actual standing over the stove and constant stirring until it has achieved full jamminess. Like making kaya, although there’s this 10-minute version that I’d like to try.
Still here? Okayyyyy… you’re masochistic, I see. If that’s the case ….
Here’s the main ingredients for onion jam aka the mother of all condiments.
Large onions. Use large onions please. In Malaysia, we call “shallots” small onions, but do not use them. Normal large onions are sweeter and milder than shallots. Both yellow and red onions are fine.
Butter and olive oil. Add butter for the flavour. You want flavour town right?
Italian herbs. The original recipe calls for thyme. We didn’t have any and substituted with oregano. To be honest, it won’t make much difference … unless you’re Italian 😉
Brown sugar. This helps the onions become jammy and adds a touch of sweetness. You can use white sugar, but brown sugar will deliver better results. We went really crazy and used molasses.
Sherry vinegar. The addition of an acidic component balances the sweetness with some tang.
There you go, simple pantry ingredients. You should totally go and make it NOW.
But … but … Alex, didn’t you just say onion jam takes two hours to make?
I did. But I discovered recently that you might not need that long, if you’re making a smaller amount.
I actually found this out by accident. The original recipe calls for 1kg onions but we only had 250g at home. Since we didn’t want to go out to buy just one item, hubby (the official onion jam guy) made do with whatever we had.
To our surprise, the desired level of caramelisation and browning happened in roughly a quarter of the original cooking time. This particular experience seems to imply that cooking time corresponds to the amount of jam you’re making. However, we’ve not done this often enough to confirm my theory. I’ll update this post once we make onion jam again.
Whether it takes 20 minutes or 2 hours, I can say this with certainty: onion jam is worth every second of your effort. Have fun!!
- 250g yellow onions
- 2 garlic cloves (original recipe was 1)
- 1 tbsp olive oil
- 35g butter
- 35g brown sugar
- pinch of dried oregano or thyme
- 1 cinnamon stick
- 60ml sherry vinegar (See Recipe Note 1)
- Salt and pepper to taste
- Slice up onions.
- Chop up garlic
- Melt butter in a heavy-bottomed pan over high heat.
- Add onions and garlic, and stir well to coat with butter. Then add sugar, oregano, cinnamon and some salt and pepper.
- Reduce heat and cook uncovered for 10 minutes.
- When onions are soft enough to break when pressed against the side of the pan with a spatula, pour in the sherry vinegar.
- Simmer everything, uncovered, over high heat, to reduce the liquid. You must stir frequently to avoid burning. This process may take about 10-15 minutes.
- Once the onions are a deep brown colour and sticky and syrupy, draw a spoon across the bottom of the pan. If this clears a path that fills rapidly with syrupy juice, your onion jam is ready.
- Leave to cool in the pan, then scoop into sterilised jars and seal. This can be eaten straight away or kept in the refrigerator for up to 3 months.
- The sourness of sherry vinegar will differ from brand to brand, so getting the right level that suits your tastebuds might need some trial and error on your part. One way might be to add LESS first, since most people prefer less sourness in their onion jam.
- How do you eat onion jam? It's a versatile little condiment. Use it as burger topping. It can serve as a condiment with roasted meats and poultry or grilled fish. Treat it as a sandwich spread. Slather a slice of toast generously with onion, add some sharp cheese such as aged cheddar or gorgonzola, and broil for a minute or two until cheese is melty. Heavenly (that's also the description of my dinner tonight)