Pozole Rojo

Place the pork chunks and optional bones in a large stockpot and cover with 12 cups of water. Add the quartered onion, 4 cloves of the garlic, bay leaves, and 1 tablespoon salt.
Bring to a boil over high heat, then skim off any grey foam that rises to the surface with a spoon. Reduce heat to low, cover partially, and simmer for 1.5 hours, until the pork is very tender when pierced with a fork.
While the pork simmers, toast the guajillo and ancho chiles in a dry skillet over medium heat for 20 seconds per side until fragrant, then place them in a small pot, cover with 2 cups water, and simmer 10 minutes until soft.
Drain the softened chiles, reserving 1 cup of the soaking liquid, and blend the chiles with the reserved liquid, remaining 2 cloves garlic, and the oregano until completely smooth. Strain the sauce through a fine mesh sieve into a bowl, pressing with a spoon to extract all the liquid; discard the solids left in the sieve.
Once the pork is tender, remove it from the broth with a slotted spoon and set aside; discard the bones or pig's foot, bay leaves, and onion quarters from the broth.
Return the pork to the pot of broth, stir in the strained chile sauce, and bring back to a simmer over medium heat.
Add the drained hominy and simmer uncovered for 30 minutes, stirring occasionally, until the flavors meld and the broth turns a deep brick red.
Taste the broth and add more salt as needed; it should taste well-seasoned, not flat.
Ladle the pozole into deep bowls, making sure each bowl gets plenty of pork and hominy along with the broth.
Set out bowls of shredded cabbage, diced onion, sliced radish, lime wedges, and cilantro at the table so everyone can top their own bowl to taste.

Straining the blended chile sauce through a sieve removes tough bits of chile skin, giving the broth a silky texture instead of a gritty one.

Skimming the foam in the first few minutes of boiling is what keeps the final broth clear and clean-tasting rather than cloudy.