Behold the humble onion! Workhorse of the kitchen, flavor base of soup and stew, pungent addition to stir fry and salad – but so rarely given a starring role. French Onion Soup, certainly – but people are often distracted by the bread and cheese, and miss the rich sweet flavor of the soup itself. And otherwise?
Twenty years ago I was doing food sampling in high end supermarkets (“Would you like to try the fresh monkfish from our In-Store Fresh Seafood Department? It’s a meaty fish, with a mild white flesh…”) These stores also had actual kitchens out on the sales floor (long gone, now) and demo chefs, who (unlike me) had real culinary training. They were there not just to sample product, but to demonstrate technique and give people ideas, help people really learn how to cook. I was sent to different stores, but had some regulars, and got to know the chefs with schedules like mine reasonably well.
And one of them, at some point, made onion marmalade… I was charmed, and I’ve been making it since. I never wrote the recipe down until today, so I’m sure it has morphed in my hands (I don’t think the original included bacon… and I’m not at all sure when balsamic vinegar, specifically, joined in) but the basic concept is the same.
Onions actually have a high sugar content. We don’t notice that, usually, because of the pungent oils, but the sugar is the reason it browns so beautifully, and that caramelized sugar is a major part of the flavor. (Even concentrated like this, I have not heard of the sweetness of the sugar being an issue for anyone – but if you are sensitive, pay attention. It doesn’t bother me.) When you cook onions slowly like this, they melt down into this wonderful concentration of flavor, which then can be served as a condiment with meat or beans, or as a spread on crackers or bread.
I used bacon in this recipe, but I want to be clear that bacon is purely optional – I have used just olive oil in the past. The smokiness of bacon adds depth of flavor, but the other ingredients are strong enough that you don’t really pick it out as an individual taste or texture. I’ll make it either way, depending on who will eat it – and whether or not I have bacon handy!
First, the pan. Because you want to cook this as slowly and gently as possible, take the heaviest pan you have… for a low, even heat. On the other hand, ideally this pan would also be non-reactive and smooth, so a cast iron pan is not ideal (unless it is very well seasoned.) Now, since for various reasons I have Too Many Pans for any sane person, I have the perfect one for this – an enameled cast iron pan. If you do not… a multi-ply stainless might be best, or a good nonstick or anodized heavy cast aluminum pan. I would not want plain aluminum, because we’re going to add vinegar… it needs to be non-reactive.
Put the pan over very low heat to start heating up. Then take bacon (if you choose to use it) and chop it very finely. I buy Bacon Ends and keep them in the freezer, then hack off a piece when I want it for cooking – but I’d guess this to be about two strips of the more typical sliced bacon. You want to render the bacon out – melt as much of the fat as possible, so you have the liquid fat to coat the onion, and tiny chewy bit of meat, but no annoying bites of fat… Depending on your pan and your stove, this will take anything from 10 to 20 minutes. I cooked this for 20 minutes – you can see the melted fat, and the meat beginning to brown.
While that is cooking, slice the onions. I used three large onions – if yours are smaller, use more. (Sorry, I should have weighed them…) This is the best time of year for this recipe, really – the onions are at their freshest, and have the greatest concentration of juice and volatile oils. (And if they make you cry – they will…) Peel and quarter the large onions, and then slice them as thin as you can. If you like to use a mandoline or a food processor, this is a good time – their slices are too thin for some purposes, but great for this.
Once the bacon is fully rendered (or the pan and two tablespoons of oil are heated, if you use that – yes, that’s more oil than I use for a typical saute) add the thinly sliced onion, and stir it around to coat it fully with the fat. Then, maybe, set a timer… or stay in the kitchen and watch… or… this is going to take an hour or so, but it’s not your time. You do need to look in periodically, and stir it all around, and check to see when it is done. I set a timer (because I get distracted) and check and stir every 15 minutes, twice (so for half an hour) and then every 10 minutes, just to be sure, maybe every 5 minutes, after an hour – You don’t want to burn anything. And you can see how much it cooks down… and the way the caramelized onion juices brown on the pan. This batch cooked for one hour and 15 minutes – but it does vary. The pan, your stove, but also the juiciness of the onion… I can’t give you a definite time – watch it closely at the end.
At this point, add balsamic vinegar. I used 2 tablespoons here – if you don’t like the vinegar taste you can cut that to one, but I would not go lower. Balsamic vinegar has its own sweetness to go with the sour, and it really helps bring out the flavor of the onion. Then keep stirring – the liquid will help it cook down even a little more, until it is really concentrated. Then I let it cool a little in the pan – you can transfer it to a heatproof container at once, if you prefer. Once the onions are out of the pan, since you still have the fond – the caramelization – deglaze with a tablespoon of water, then add it back to the onion and stir. You don’t want to lose any of the flavor!
And that’s it. Not a lot of effort, really, but time… you could let this cook while you watch a TV show and check on commercials. I made this batch as a gift – it’s a very nice Something Unusual From My Kitchen, especially for someone who enjoys good food but doesn’t cook much. A double or triple batch in December takes longer, but yields multiple little 4 ounce jars of Thinking Of You goodness… And definitely make enough for yourself!
Onion Marmalade - rich umami flavor with a sweet/sour balance - wonderful as a condiment or spread.
10 minPrep Time
2 hrCook Time
2 hr, 10 Total Time
- 2 strips bacon (or 2 T olive oil.)
- 3 large onions
- 2 T balsamic vinegar
- Set a heavy pan to heat over very low flame.
- Chop bacon very fine. Place in the pan, and let cook very slowly, to render out the fat. (Depending on the pan and the stove, this will take at least 10 minutes, and as long as 20.) Or - heat oil in pan.
- Peel and quarter onions. Slice thinly with sharp knife or mandoline.
- When bacon is fully rendered, add onions to the pan, and stir well, to cover them with fat. Then let it cook down over low heat, stirring every 10 minutes or so, until onions are caramelized and cooked down. This may take an hour or longer.
- When onions are cooked down, add balsamic vinegar. Stir it in well, then continue to stir for a few minutes to cook onions down even further, and work in the vinegar.
- When done, remove onions, and deglaze the pan with 1 T water. Add to the onion mixture.
Serve a dab on the side with meat or beans, or as a spread on crackers.