Put the chiles into a small bowl and cover with hot water; set aside. In a large heavy bottomed pan with a tight fitting lid, heat 3 tablespoons olive oil. Generously season the pork with salt and pepper. Brown the meat well on both sides, about 5 minutes per side; remove the meat and set aside. Add the onion, pepper, garlic, cumin, thyme, and bay leaf; fry until softened, about 5 minutes, scraping up the browned bits in the pan. Stem and seed the soaked chiles reserving the soaking liquid; hand tear them into the pot. Return the meat to the pan along with any accumulated juices. Top the meat with the tomatoes. Pour in the chili soaking liquid, straining out any seeds, until it almost covers the meat; add water if you need more liquid. Squeeze the orange and lime juices into the pot and add the rinds. Bring the liquid to a boil, reduce the heat, cover, and simmer for about 1 1/2 hours, or until the pork is very tender. Remove the meat to a platter and cover to keep warm. Strain the braising liquid and reserve.
Shred the pork. Add some of the reserved braising liquid if the meat is dry. Take a tortilla and place about 2 tablespoons of the mixture on top. Garnish with the avocado, radishes, and Salsa Verde; fold the sides up and serve.
Put the masa harina in a bowl and mix in the salt. Add about 1 cup warm water and mix with your hands; add more water as needed until the dough comes together. Knead for a few minutes to smooth the dough out. The dough should be firm and springy and should not stick to your hands. Test by forming a small disk, if it cracks around the edges you need more water.
Place a piece of heavy plastic (like from a garbage bag) onto a tortilla press. Form a 1 1/2-inch ball of dough and place it in the center of the press. Top with another piece of plastic, close the press, and push the lever down to form the tortilla. (Alternately, the dough balls can be rolled between plastic sheets with a rolling pin.) Open the press and remove the top layer of plastic. Carefully peel the tortilla off the bottom plastic and place it onto a hot, ungreased cast iron skillet; cook for about 1 to 2 minutes per side. Remove the tortilla and place it on a clean tea towel; keep it covered to keep it soft and pliable. Continue until you have used up all the dough.
Yield: 20 (6-inch) tortillas
Prep Time: 20 minutes
Cook Time: 40 minutes
Tomatillo Salsa Verde:
Bring a pot of water to a boil and add the tomatillos, jalapeno, onion, garlic, and 1 tablespoon salt. Reduce the heat and simmer gently for 5 to 10 minutes until the tomatillos are soft but have not burst. Add the cooked vegetables to a blender with the cilantro leaves and lime juice. Pour in 1/4 cup of the reserved cooking liquid and process to a coarse puree. Taste and adjust seasoning with more cilantro, lime juice, or salt.