In a large Dutch oven, heat the olive oil over medium-high heat. Mix together the flour and salt.
Coat the pork cubes in the flour mixture and add the pork to the pan, making sure not to overcrowd the pan. Depending on the size of your pan, you may need to do this in two or three batches. Cook for 3 to 5 minutes a side and flip until the pork is browned on all sides. Remove the pork and set aside.
Add the onions to the pan, scraping the bottom to remove any browned bits. Cook for 5 minutes, until softened.
Add the garlic, oregono, and cumin and cook until fragrant, about 1 minute.
Add pork back to the pan and add 1/4 of the chicken broth, scraping the bottom to release the browned bits on the bottom of the pan.
Add the remaining chicken broth, green chilis, and tomatoes. Bring the mixture to a boil before reducing the heat to a simmer. Simmer for 2 to 3 hours, partially covered, until the pork is tender. Larger pieces of pork will take longer to become tender.
If using the potatoes, add them for the last 30 minutes.
Ladle the green chile stew into individual bowls and serve with sour cream, lime, and cilantro. Serve with flour tortillas on the side.
