If using dried beans, soak them in 8-9 cups of water overnight or for about 8 hours and then rinse before using (measure the 2 cups after soaking). If using canned garbanzo beans, pour them in a strainer and rinse the gel off.
Preheat oven to 325 degrees F
In a large Dutch oven (or oven-proof pot), heat 1 Tbsp oil over medium high heat. Season the pork with salt and pepper and brown the pork on all sides. You will need to work in batches to get a good sear. Do not overcrowd the pan. It took me 3 batches and I added the second Tbsp oil in the second batch. It takes about 5-8 min. per batch.
When all of the pork is seared, return all the meat to the pot and add the onions and garlic. Saute the onion and garlic with the pork over medium heat, stirring occasionally for around 5 minutes.
Add garbanzo beans, oregano, ancho spice, chipotle spice, cocoa, chicken stock to pot and stir to combine. Salt and pepper to taste at this point.
Bring the mixture to a boil, stirring occasionally, and then cover the pot and place it in the oven for about 2 hours, or until pork is tender
Ladle the pozole into bowls and garnish and serve.