When I first decided to make panuchos, Alison was totally on board...until I mentioned the pickled onions. Why would you make a delicious meal and then ruin it with something gross like that, she wondered. You don't have to eat them, I told her, but I think they'll be nice.
There was a misunderstanding, you see. She heard "pickled onions" and thought of those stunted baby onions soaked in vinegar and sold in jars. Why indeed would I put those on my delicious food? Why indeed do those onions exist at all? I can't imagine anyone enjoying them. Even if you had no taste buds, their texture would put you off.
Of course I had no intention of putting pickled white baby onions on our panuchos. The pickled onions I had in mind are a Yucatecan delicacy, like panuchos themselves.
Like most things beyond the limited range of North Mexican, Tex-Mex, and Mexi-Cali cuisines (eg burritos, baked enchiladas, chile con carne, and those U-shaped hard tacos), I had never heard of this condiment. In fact, these pickled onions belong to the list of foods I would never have expected to be part of Mexican cuisine, like duck en pipián.
Once she tried them, Alison agreed they are delicious, but insisted I learn their Spanish name, you avoid evoking the jarred monstrosities. In another cookbook I learned they are called cebollas en escabeche.
So what are they? Well, to start, they are red onions, not white; and they are full-grown, not baby-sized; and they are sliced, not whole.
The pickling is a bit problematic, actually, as the usual way to pickle something in European cooking is to soak it in vinegar. To get vinegar you need wine, and Mexico is not a major producer of wine (much to the dismay of the Spanish colonists).
Obviously vinegar can be and is imported now, but how did they make the dish traditionally?
A running theme of this blog is that I have a lot of Mexican cookbooks, and all of them include recipes for certain classic dishes. The Two Cooks version of pickled onions calls for red wine vinegar. Other versions use white wine or even cider vinegar. There's even one which doesn't call for vinegar at all. It can, apparently, be done with boiling water.
The other common natural pickling agent is citric acid, i.e. the juice of any citrus fruit, which is and always has been readily available in Mexico. Yet strangely, citrus juice is not used in this recipe until after the onions have already been pickled! However, all versions call for habanero chilies, so perhaps the acid from these is enough to do the job on its own.
I have made these pickled cebollas twice, once using red wine vinegar and once using white wine vinegar, and I haven't noticed a major difference in taste. In both versions, more than half the liquid is still just boiled water, so I'd say the more important thing to get right is the seasonings. Some versions call for nothing more than the chilies, but I stand by the Two Cooks version, which includes allspice berries, Mexican oregano, and epazote. These have been my favourite Mexican seasonings ever since I discovered them, and I use them at every opportunity.
So, begin by slicing red onion very thinly. I cut the onion in half first, because I don't want rings, but this may not be the most attractive way to present the finished product. It is, though, only a garnish.
Then you need some habanero, roasted and finely chopped. You can leave the seeds out if you include vinegar, but if you're going with just water I'd include the seeds, as you'll need as much acid as possible.
Then you need some allspice berries (lightly crushed), some epazote, Mexican oregano, and maybe a teaspoon of ground cumin.
Put all this in a bowl. Add vinegar until the onions are about a third of the way to being covered. Then pour in boiling water to cover the onions. If you're not using vinegar, just cover with boiling water.
Seal the bowl with clingfilm and set aside for about four hours.
But that's not the end. After the onions have pickled, drain most of the liquid (and remove the allspice berries) and place the onions in a serving bowl. Then pour the juice of one bitter orange over them.
Bitter orange is a Mexican citrus fruit that does but seem to be available outside Mexico. Obviously I've never had it myself, but apparently it tastes life a cross between orange and grapefruit, so you can make "mock bitter orange juice" by mixing the two fruits. It is this bitter citrus zing that makes this such a delicious condiment. And the best part is that there's usually plenty left over to put on sandwiches and such for the next few days.
One of my cookbooks calls these "pink pickled onions" in English, and indeed, though they start out as standard red onions, they end up uniformly pink by the time they're ready to serve.
I forgot to take a picture while they were in the serving dish, but I do have a photo of the last of them sitting on a flour tortilla (store-bought), moments before I filled it with chicken and probably too many chipotle peppers. I'm not sure the picture does them justice, but at least you can see how pink they are.
If you are ever cooking a Yucatecan dish, you must include these. In fact, you should probably make them anyway. They're that good.