Onions: the staple in every kitchen, everyone’s favourite alium and probably the most versatile vegetable in the kitchen. I think it was the great Escoffier (one of the fathers of modern french cooking and founding chef at the Ritz) who said, albeit in French, “If you want to cook food well, start with an onion and go from there.” And even if he didn’t say it, and the story is apocryphal, he should have said it. Due to its variable flavour profile, how easy it is to grow and consequently how cheap the onion is, it has become the backbone of cuisines spreading from Southern Asia through the Middle East, Eastern Europe to Italian, Spanish and French cooking. In fact, the only major world cuisine I can think of that doesn’t heavily rely on our favourite bulbous vegetable is Japanese.
In restaurants there was quite a trend a few years ago (and actually still going strong) for burnt onion ashes – a peculiar trend for me of which I’m yet to be convinced. I’ve always thought onions are at their best either fresh and crisp in a salad (preferably this persian one) or caramelised so the natural sweetness of the onion comes out. I think, for me, the first experience of caramelised onions that sticks in my memory is what in Australia we refer to as “A Sausage Sizzle”. Basically after footy (rugby union) matches the dads would be barbecuing sausages (always split down the middle), eggs (until you’ve had a runny egg on a sausage sandwich you haven’t truly lived) and of course onions. Then, the whole thing would be stuffed between two slices of wonderwhite bread and drowned in ketchup – absolute heaven. Especially as a reward for having played two or even three full rugby games that day. The onions stick in my mind though, they were sweet and jammy and if I’m honest often a little burnt. I’ve spent a long time working out the perfect way to get those onions just right (without the burnt flavour) and this way is nearly perfect in my opinion. The trick: slow-cooked onions.
Cooking these slow-cooked onions is remarkably easy and they keep for over a week. You only need a pan and some greaseproof paper, and you get to sound very knowledgeable when you tell people fancy things like “make a cartouche and they’ll cook better” (a cartouche is just another way of saying a circle of greaseproof paper). You can mix up the onions by crumbling in some chorizo to make amazing chorizo jam, or by adding some balsamic vinegar for the last 20 minutes of cooking to make balsamic onions. Once the onions are made, they are amazing either on their own or in a burger, as part of an onion gravy, mixed into mince for an amazing meatloaf or stuffing or, as I often do, as part of the filling for an amazing Quiche Lorraine. At Christmas, my family takes these onions and mixes them through mashed potatoes with frozen peas – it’s absolutely delicious – and the cooking is super easy!
Slow cooked onions
- 2 onions
- Splash of olive oil
- Greaseproof paper
- Slice the onions very finely and place in a large saucepan (ideally with a heavy bottom) with a fitting lid. Season with salt, pepper and a splash of olive oil.
- Take a square of greaseproof paper about the size of your pan. Fold it in half lengthwise and then again so you have a smaller square. Fold the smaller square along the diagonal to form a triangle. Then keep folding the triangle in half a couple more times. At this point you should have a thin triangle. Slice the tip off the triangle and slice the other end off the triangle so that the length of the piece remaining stretches from the middle of the pan to the edge, then unfold the greaseproof paper and you’ll have a circle with a hole in the middle. (This is a cartouche). The aim here is to let as little moisture as possible escape from the onions, the moisture will stop the onions from burning or colouring too much and will allow the natural sugars to be drawn out.
- Place the cartouche on top of the onions (squidging them down) and place the pan on the lowest heat for around an hour or until soft, sweet and jammy. Make sure to stir the onions every 15 minutes or so to make sure they don’t catch.