Remove the stems from each chile shaking out as many seeds as possible and place in a large bowl. Cover chiles with boiling water and top with an upside down plate to keep submerged. Let sit until softened, at least 30 minutes.
While chiles are softening, heat a deep pan over high heat and drizzle with canola oil. Sprinkle pork chunks with 2 teaspoons of the salt, pepper and 1 tablespoon of the oregano. Brown pork in a pan until pieces start to form a crust. This should take about 7-8 minutes.
Once the pork is seared, remove from pan and place in the slow cooker insert.
Add chicken broth, hominy and remaining 1 tablespoon oregano to the slow cooker.
To make the red chile paste, place softened chiles and 1 1/2 cups of the soaking liquid into a blender or food processor. Add onion, garlic, and remaining 1 teaspoon salt then puree until smooth.
Place a fine mesh strainer over a large bowl and pour chile paste over the strainer. Use a spatula to push the chile paste through removing any large pieces. Taste paste for seasoning and add salt or pepper if needed.
Pour chile paste into the slow cooker and stir well. Heat on low for 8 hours or high for 4 hours.
Add lime juice to the posole before serving, being sure to add salt or pepper if necessary. Serve stew in bowls with optional garnishes.
Notes
This dish is great with pork or chicken neck bones which I pick up at my local hispanic grocery store. It's great for freezing as well!