In a large pan over medium-high heat, heat the olive oil and cook the pork pieces in batches, making sure not to overcrowd the pan. Brown the pork on all sides and remove from the pan and set aside.
Add the onion to the pan and cook for 5 minutes, until softened. Remove half of the onion and place it in a blender or food processor. Set aside.
Add the pork back to the pan with the remaining onions and add the salt and 5 cups of broth. Simmer for 1 hour.
While the pork simmers, turn on the broiler to 500°F and place the oven rack at the top of the oven.
Line a cookie sheet with parchment paper (or foil) and place the poblanos, tomatillos, jalapeños, and the garlic head (with the top cut off) onto the prepared pan.
Place the pan under the broiler for 5 minutes, or until the chilis begin to blacken, watch closely. Turn the chilis and tomatillos over and broil for another 5 minutes to cook the other side.
Remove the pan and place the poblanos in a large ziplock bag for 5 minutes to steam, then remove the skins. Add the poblanos and the tomatillos to the blender (or food processor). Remove the seeds from the jalapeños and then add them to the blender. Squeeze the garlic from the peel and add to the blender. Add the remaining 3 cups of broth and the cilantro and blend until smooth.
Toast the cumin seeds in a pan for 1 minute, then remove and crush in a mortar and pestle (or in a molcajete). Then add the cumin and oregano to the prepared green sauce.
After the pork has cooked for an hour, pour in the green sauce and add the hominy.
Simmer over medium low for a minimum of one hour or two hours is even better. If the sauce gets too thick, add some water or chicken broth, as needed.
Place bowls of garnishes on the table, serve the bowls, and allow everyone to season the way they wish! Enjoy!