I made this from the leftover sheep’s liver I prepared a few days ago. This is a stew with a passionate heart. The flavors in here are strong: sour red wine, savory liver, pungent-sweet epazote, sweet cinnamon and clove, smokey Spanish paprika. Uninhibited too are the textures: thick, buttery lima beans; large, crunchy croutons; tender chunks of liver; melty, tender sliced vegetables.
My friend’s brother-in-law, grateful for my friend’s help, gave him the liver of one of his sheep. In turn, my friend passed the liver onto me. So, I wanted to do something different from the traditional liver with onions. (Sorry, Mom.)
I found the recipe for calf’s liver with sorrel sauce in one of my favorite Spanish cookbooks, The Foods & Wines of Spain, by Penelope Casas. Casas mentions that this dish, originating in Segovia, was traditionally made with rhubarb leaves. Rhubarb leaves, despite being toxic, have a very pleasant citrus taste. (I had to take a pinch just to see.) However, due to their known poisonous properties, Casas uses sorrel, instead. Since they are in the same plant family–Polygonaceae–and very closely related, they share similar qualities, including that illuminating tartness from all the oxalic acid.
I did make a few modifications to the recipe.
As the head cheese rests in my fridge, I, in the meantime, to forget about all the coagulation in my kitchen, distract myself learning a few things.
First I turn to Harold McGee. In his book, On Food and Cooking, he makes a brief mention of collagen, a protein responsible for connecting tissues, comprising “about a third of all the protein in the animal body” (130). Because it’s mostly concentrated in the skin, tendons, cartilage and bones, it makes sense that Diana Kennedy emphasized the importance of using the skin from the cheeks. According to McGee, the word for collagen, etymologically Greek, means “glue-producing.” When heated in water, it can dissolve into gelatin. In other words, when cooked, it softens. (As it turns out, we and other animals are born with more collagen, and as we age it disappears; hence why veal is more gelatinous and tender.)
While I was picking apart the head, tugging at the jaw and digging my fingers through the eye sockets and other cavities, I discovered all types of different fat compositions. The snout was purely skin and fat.
Collagen, according to Wikipedia, is the most abundant protein found in mammals, making up a quarter to a third of whole-body protein content. Its structure is long and fibrous, and its repeating sequence of amino acids, and its composition of glycine, proline and uncommon derivative amino acids, make it both unusual and a source of interest among microbiologists. But, what’s important to know is that its whole raison d’être is to connect tissues together: fat to skin, muscles to tendons; and, when collagen is hydrolyzed–that is, irreversibly isolated and cleared of any debris–it becomes gelatin. It is the gelatin that will hold all the meat and flavor together in the head cheese. Not incidentally, pig head is a major source of commercial gelatin.
Since the original intention was to take advantage of the connective power of the pig’s head, I decided that head cheese was the best choice. I have been giving mucho amor to my Mexican cookbooks, so I began there. Immediately I discovered in Diana Kennedy’s The Art of Mexican Cooking a recipe that seemed simple enough, that highlighted the natural flavors of the head–she calls for water rather than a stock–by creating a broth, then reducing it down into a sort of impatient demi-glace on high heat, thus concentrating the rich and deep properties of the flavors. It was a recipe designed for a smaller head, about half the weight of ours, so we merely doubled everything.
When my grandfather told me that he was going to make scrapple, I had the immediate and reasonable urge to acquire a pig’s head. Traditionally, he uses the head because of its beautiful fat content and industrial-strength gelatinous collagen. But the lamentable fact is some parts of the animal are simply undesirable. So he has accustomed himself to using the far-more-accessible feet, instead. I recall several moments of him speaking about the enchanting properties of the pig’s head. So, naturally, when I ordered the head from my butcher, I envisioned a gasp and a huge smile. In return, however, I received a plain response of, “Please don’t.” As it turned out, he had already purchased the feet and was not interested in keeping them or the head in the freezer. That was understandable. But now I have a 13.5-lb. pig’s head. What to do?
Well, first, I and my fellow cooks removed it from the box.