Bacalao has enjoyed tremendous popularity throughout the Mediterranean for centuries, but you may be surprised to know that the cod used to make it comes from cold Northern Atlantic waters. The prolific Basque fisherman of the 15th and 16th centuries were a big part of establishing the obsession for bacalao, so perhaps then, it’s not so surprising that this Bacalao dish is one of the most famous exports from the Basque region. There are a few different competing origin stories for bacalao al Pil Pil, and I’m not really sure which, if any, have any basis in reality. My favorite, though, goes that this dish came about accidentally because of the constant rocking of the boat as the cod was cooked on board by fishermen.
What is Bacalao al Pil Pil? Reconstituted salt cod is cooked slowly in a lot of oil, pulling out a lot of the juices and collagen from the fish. While cooking, the pan is moved constantly, emulsifying the oil and fish juices into a sauce. This is a deceptively simple dish with only a few ingredients, but you’ll be amazed at how huge the flavors are. Making pil pil is all about the technique to get the sauce right. Once you understand the basic idea, though a little bit of work, it’s a pretty easy dish to make.
Because the sauce is a fairly delicate emulsion, there are a couple things to remember. First, you don’t want the oil too hot, or it won’t come together. The sauce will thicken significantly as it cools. Don’t let it cool all the way down to room temperature, but it’s best if it isn’t served extremely hot. Some people cook the bacalao skin side down, and some skin side up. Because the main thing emulsifying the sauce is collagen from the fish, and the collagen is most concentrated and available in the skin, I always prefer to do this skin side down for maximum emulsifying power. I also think that the fish is easier and more pleasant to eat served skin side down.
It’s really hard (not impossible) to get the sauce to fully emulsify with the fish still in the pan. It’s easier to remove the fish when it’s cooked through, and then whisk the sauce together. Even better than a whisk, I’ve seen many Spanish chefs use a little miniature strainer to stir things together. If you want the best possible emulsification, you can always pour the sauce into a narrower container and use a hand blender. You should not need to use any flour or cornstarch.
3 or 4 center-cut bacalao (salt cod) loin pieces
5 or 6 cloves of garlic, peeled and cut in very thin slices
2 or 3 guindillas (or other small, hot peppers, such as cayenne) cut in half and seeded
1¾ cup oil (I use a 50/50 mix of extra virgin olive oil and canola)
1. Reconstitute and desalt the bacalao: Rinse off the bacalao and cover with a generous amount of cold water. Leave covered, soaking in the fridge for at least 2, preferably 3 or 4 days, changing the water several times each day. When ready to use, drain, pat dry with a paper towel, and cut each loin piece in half, removing the central spine.
2. Add the oil to a large, heavy-bottomed pan and turn on a medium-low flame. Add the garlic while the oil heats up. Stir regularly, and when the garlic begins to sizzle, add the hot peppers, and continue cooking until the garlic begins to brown. As soon as the garlic gets a very light golden brown color, turn off the heat, strain it and the peppers out of the oil and let drain on a paper towel. Reserve for later.
3. Let the hot oil rest for about 2 minutes, and then carefully place the pieces of fish, skin side down in the pan. Let them sit in the hot oil for another 2 minutes, and then turn the heat on low to medium-low. You don’t want the pan sizzling, you just want to gently poach the fish in the oil.
Note: At this point, you will see little white globules coming out of the fish into the oil. This is exactly what you want. The more the better.
4. With the fish in the pan on low heat begin to agitate the pan, moving it around constantly. You want to get the oil moving as much as possible without splashing out of the pan or breaking up the delicate cod. Ideally things should keep moving for about 15 minutes.
If your fish pieces are too tall, and the tops are not getting cooked, you can place a lid on top of the pan for a couple minutes to steam the tops of the fish.
When the fish is thoroughly cooked through, and very flakey, remove from the heat and carefully set aside on a plate. Be careful handling the fish! It will be very delicate and fragile at this point.
5. Finish the sauce: Turn the heat off on the stove. Scoop out any chunks of fish or skin that have flaked out during cooking. With the heat off begin whisking together all of the contents of the pan, while moving the pan. You can do this with a whisk if you like, or, a small fine mesh strainer is a great tool for this task. It will take a couple minutes of whisking for the sauce to really smooth out and come together. If you aren’t getting a good enough emulsion, let the oil cool a little more, but also, you can use an immersion (hand) blender to really thicken the sauce, if you want.
Note: You will notice that before you start this step that the sauce is likely to look like a mess of fish juices floating in oil. That’s normal. The point of this step is to emulsify it together into a nice sauce.
6. To serve, place the cooked bacalao on a plate, and top with the sauce, then garnish with some of the fried garlic and chile. I like to serve this with potatoes and some sort of green vegetable, and, of course, good bread to mop up the sauce!