Until you taste it, there is little to recommend vinegar-braised pork shoulder. The steam from the pot, heavy with acetic acid, burns the eyes of the cook who checks on it. And stews rarely allow for pretty presentation.
But after two hours of slow cooking, the harshness has disappeared and the ingredients are transformed. The pork, stoic to the end, at last sighs and mingles its juices with the vinegar. Sweet tomato paste blunts the acidic bite. What's left is fork-tender pork swimming in a tart, complex, brick-red liquid. "An instant hit," declared Melissa.
I first saw the dish in The Art of Eating #68, which you can still order if you'd like the full recipe. That issue included Ed's inspiring article about making red-wine vinegar alongside recipes that used it. Despite the three-day preparation time, it would be hard to find a simpler dish. Rub the pork shoulder in salt; let sit for 24 hours. Marinate the meat for 24 hours with spices and a mix of vinegar and water—I used 1 cup of red wine vinegar and 3 cups of water, but you might choose 2 cups of each if you use a commercial vinegar, which has lower acidity and less flavor than homemade versions. Cut pork into big chunks and lightly simmer them in half of the marinade (diluted with an equal amount of water) in a partially-covered pot until the meat falls apart with little effort, about two hours. Add a dollop of good tomato paste about an hour into the cooking.
Ed suggests serving the broth in one course and the meat in the next, but I combined them into a single dish perfect for a winter evening. Lay stale bread onto the bottom of a bowl, top with rosemary roasted root vegetables and the cubes of braised meat, and ladle the liquid into the bowl. The bread will soak up some of the broth and become soft and flavorful.
Serve a tart, fruity red wine alongside the stew. A Beaujolais (not Nouveau), a light Pinot Noir, or a Blaufränckish should all work. Don't bother with the Da Vinci Chianti Classico Riserva, which I received as a sample and tasted that evening. The best I can say about the wine is that it's inoffensive and mediocre.