Hand on heart, this is the quickest and easiest pickle you’ll ever make. It’s traditionally served with pork pibil tacos or any other pibil-style dishes. The acidity of the pickle combined with the sweetness of the onion cuts through the fattiness of the pork – it’s a match made in heaven. If you are worried about heat, use only a quarter of a habanero chilli or leave it out altogether, it tastes good with or without it. This pickle is also delicious in cheese sandwiches or with a steak.
Serves 4–62 small red onions, peeled
½ small red habanero chilli (optional)
60ml extra virgin olive oil
60ml apple cider vinegar
¼ tsp dried Mexican oregano
½ tsp flaky sea salt
½ tsp freshly ground black pepper
Cut the onions in half lengthways from tip to root and slice them thinly, making sure every slice is the same thickness. Cutting the onion lengthways instead of around the ‘equator’ like you might usually do may feel a little unnatural, but if you are doing this by hand with a knife (as opposed to using a Japanese mandolin, like I do), you’ll notice that it’s easier to get slices that are a consistent thickness, which is of paramount importance for this recipe. If you have variations in thickness, you’ll find that the slices pickle at different times so you will have some soft slices and some that are still crunchy. But every food processor comes with a slicing disc that will do all this for you.
Thinly slice the habanero chilli (if using), making sure to wash your hands well with plenty of cold water and soap both before and after touching the chilli. I don’t bother deseeding the chilli (no self-respecting Mexican would!), but if it makes you feel better, go ahead and deseed it – just be warned that doing so doesn’t get rid of the heat.
Boil your kettle and put the sliced onions and chilli in a medium-sized heatproof glass bowl (or something non-reactive). Pour the boiling water over the onions and chilli until they are all covered. Soak for 2–3 minutes – this partly cooks the onions and takes out some of their harshness. Set aside while you get the pickle going.
Combine the oil, vinegar, oregano, salt and pepper in a glass jug and mix with a small whisk or fork until well combined. Taste and check the seasoning – it should be sharp and well-seasoned, so add a little more salt and pepper if needed.
By now your onions should be almost translucent and the water should look a little cloudy. This is a sign that the onions are ready, so carefully strain the contents of the bowl, making sure to get rid of as much water as possible. Return the onions and chilli to the warm bowl – this is super important! Don’t use a clean bowl. You need the same bowl that you soaked the onions in, as it’s hot and that will help with the pickling.
Give the pickling liquid one final whisk and immediately pour it over the hot onions and chilli. The heat of the bowl and the heat of the onions will help the liquid to emulsify and it will kickstart the pickling process. Mix everything well with something non-reactive, like a rubber spatula or a wooden spoon, making sure everything is coated with the pickling liquid. My grandmother always warned us not to work with vinegar and metal utensils, as they may react chemically. A lot of the metals are now okay to use, but I keep the tradition just in case!
Set aside, uncovered, at room temperature for 1½–2 hours, stirring every half hour or so. As the onions pickle, you’ll see them getting pinker and softer. I don’t cover the bowl until its contents are completely cold. If you cover it while it’s pickling, it might sweat and the condensation will drop back into the pickle, adding unnecessary moisture to the recipe, or worse, creating an environment where bacteria could grow.
If I have leftovers, which rarely happens, I store them covered with a cheesecloth or a thin tea towel in the coolest part of the kitchen (not in the fridge) for two days max. The fabric cover allows the pickle to breathe and prevents cross-contamination. I never bother bottling this pickle in sterilised jars as it’s so easy to make a fresh batch and it tastes better.