In a large pot, heat the olive oil over medium-high heat. Add the chicken or pork and brown on all sides.
Add the onions and garlic to the pot and cook until the onions are translucent.
Add the bell peppers and tomatoes to the pot and cook for an additional 5 minutes.
In a separate pan, toast the dried chiles until fragrant. Remove from the heat and soak in hot water for 10 minutes.
In a blender or food processor, blend the toasted tortillas, soaked chiles, cumin, coriander, and oregano until smooth.
Add the chile paste to the pot and stir to combine.
Pour in the chicken or pork broth and water and bring to a boil.
Reduce the heat to low and simmer for 1 hour or until the meat is tender and falls off the bone.
Season with salt and pepper to taste.