Tinga poblana is a sensual, eat-with-your-hands experience, a traditional shredded pork dish from the Puebla state of Mexico that is eaten in a warm flour tortilla with some avocado, fresh cilantro and a squeeze of lime. I love to serve this kind of food to my friends, especially those who frequently eat in restaurants. This is soul food, the kind of hearty meal where nothing is left on a plate and where you end the night leaning back in a chair, shoes under the table, laughing, drinking and having a great, relaxed time. People who don't cook especially appreciate this kind of homey dish. Making a simple one-dish meal instead of something fancy with lots of components and sauces also takes a lot of pressure off of the cook. Add a salad, a loaf of bread and some wine or cerveza (that's beer!) and you have a party. Though potato is traditional in this dish, I don't consider it essential and I sometimes leave it out. Add it or not, it's your call. I like to use pork loin instead of fattier cuts like pork shoulder, since it makes for a cleaner-tasting dish.
1. Bring a large pot of salted water to a boil. Add the potatoes and cook until tender, about 20 minutes. Drain the potatoes and set aside.
2. Place the pork in a large pot of water. Add the onion half, the garlic and the bay leaves and bring to a boil. Reduce the heat to low and simmer gently until the pork is cooked through, about 45 minutes (you can cut off a small chunk and see if it is still pink in the middle). Remove the pork from the water and set it aside until it is cool enough to handle (discard the cooking liquid). Using your fingers or two forks, shred the meat into small pieces and set aside.
3. Break the chorizo into small pieces and fry it over medium-high heat in a large skillet or pot, stirring often, until it is completely cooked through, 8 to 10 minutes. Use a slotted spoon to transfer the chorizo to a paper-towel-lined plate. Add the chopped onion to the same skillet and cook, stirring occasionally, until soft, 3 to 5 minutes. Add the shredded pork, the potatoes, the tomatoes and the chipotle chiles and cook until the tomatoes break down and release their juices, about 15 minutes. Return the cooked chorizo to the pan and stir in the vinegar, thyme, marjoram and some salt. Continue to cook over medium heat until some of the liquid has evaporated, about 5 minutes.
4. While the pork cooks, heat a medium skillet over medium-high heat. Add a tortilla and warm for 10 to 15 seconds. Flip the tortilla over and continue to warm until the tortilla is pliable and heated through, another 10 to 20 seconds. Place on a plate, cover with a kitchen towel, and set aside; repeat with the remaining tortillas. (Or warm the tortillas in the microwave: Stack them on a plate and cover with a damp cloth, microwave for 30 seconds, and keep them covered until you're ready to serve.)
5. Place the tinga in a serving bowl or bring it to the table in the cooking pot. Arrange the tortillas, avocados, and cilantro on a platter so each diner can fill a tortilla with some of the meat and accompaniments. Pass a bowl of lime wedges around the table to squeeze over each serving.