Place the pork chunks, quartered onion, smashed garlic, cumin, oregano, bay leaves, salt, pepper, and chicken bouillon in a 6-quart or larger slow cooker. Pour in 8 cups of water.
Cover and cook on low for 8 hours or on high for 4-5 hours, until the pork is very tender.
About 1 hour before the pork is done, prepare the chile sauce. Remove the stems and seeds from all the dried chiles. Place them in a medium saucepan with 4 cups of water.
Bring the water to a boil, then reduce the heat and simmer for 20-30 minutes, until the chiles are very soft.
Carefully transfer the softened chiles and 1.5 cups (355 ml) of their cooking water to a blender. Blend until completely smooth. Strain the sauce through a fine-mesh sieve into a bowl, pressing on the solids to extract all the liquid. Discard the solids.
Remove the pork from the slow cooker and place it on a cutting board. Shred the meat using two forks. The pork must reach an internal temperature of 145°F (63°C). Discard the onion quarters and bay leaves from the slow cooker.
Return the shredded pork to the slow cooker. Stir in the strained chile sauce and the drained, rinsed hominy.
Cover and cook on low for the final 60 minutes to allow the flavors to combine.
Ladle the pozole into bowls. Serve hot with shredded cabbage, sliced radishes, cilantro, and lime wedges on the side for topping.