2. In a large pot of boiling water, blanch the pig's feet for 5 minutes. Add the bacon and cook for another 5 minutes. Drain.
3. In a large skillet, heat 2 tablespoons of the oil over high heat. Rub the beef or pork generously with salt and pepper, and brown well on all sides, about 7 minutes. Remove the beef to a bowl, add the Italian sausage to the skillet, and brown on all sides for about 5 minutes. Pat dry the beef and the sausage with paper towels to remove grease.
4. In a 7-quart stockpot, combine the beans, reserved dried beef and tongue (if using), pig's feet, bacon, brisket or pork loin, and smoked pork chops, loin, or butt. (Reserve the Italian sausage.) Add the cheesecloth bag and enough water to cover the beans and the meats by 2 1/2 inches and bring to a boil, skimming. Reduce the heat to low, cover, and simmer for 1 1/2 hours. Skim from time to time and keep checking the level of liquid, adding more cold water to keep it at the same level. Add the kielbasa and continue cooking over very low heat until the beans and all the meats are very tender, about 1 hour longer, checking and replenishing the liquid periodically. (While the feijoada is cooking, make the kale recipe; the kale can be reheated at serving time.)
5. In a large skillet, heat the remaining 2 tablespoons of the oil over medium heat. Add the onion and garlic and cook, stirring, until the onion is soft, about 7 minutes. With a slotted spoon, remove about 2 cups of beans from the liquid and add them to the skillet. Mash the beans right in the skillet with a fork. Add the orange juice and cook this mixture, stirring, for about 5 minutes, then pour the contents of the skillet back into the bean pot. Add the reserved Italian sausage, season with salt and pepper to taste, and cook over low heat for another 15 minutes.
6. To serve, remove the cheesecloth bag. With a slotted spoon, transfer the meats to a large bowl or cutting board. When just cool enough to handle, cut the sausages into thick slices. Cut all the other meats into slices. If you like bacon, slice it too; otherwise discard. You can either arrange all the meats on a large serving platter, or, for a more casual presentation, stir them back into the beans. Transfer the beans to a large serving bowl. Serve the beans and meats accompanied by rice, Stir-Fried Shredded Kale, orange wedges, and pickled chiles.
Jeremy Bailenson, founding director of Stanford University's Virtual Human Interaction Lab, is studying whether the experience of being a virtual cow will make people feel more empathy. "[Our previous work] showed that if you had occupied the avatar of another person, you showed empathy toward them," Bailenson says. "But no one had ever tried this with another species."