In a heavy-bottomed pot with a tight-fitting lid on medium-high heat sear the pork in the oil or lard, browning the meat. Transfer the meat to a bowl with a slotted spoon or a pair of tongs. Add the onion and peppers to the pot and cook until the onions are caramelized to a nice golden brown, stir frequently. Add the garlic and continue for 2 more minutes. Add the yucca, tomatillos, orange juice, beer and cumin. Bring to a boil. Turn the heat down to a simmer, add the pork, and cover. Stew the meat, stirring and skimming off fat occasionally for 2 hours. During the last 10 minutes of cooking, stir in the cilantro. The stew should be thick. Add water if it gets too dry. Top with a dollop of fresh Mexican sour cream, a small spoonful of tomato salsa and garnish by sticking fried corn tortilla shards dusted with chile powder and salt into the center of the cream and salsa and lay a few sprigs of fresh cilantro over them.