Heat a large pot or Dutch oven with vegetable oil over medium-high heat. Add the beef in batches (do not overcrowd the pan) and sear on all sides until a nice golden-brown crust forms. Remove the meat and set it aside, then repeat until all of the beef has been seared.
Once all of the meat has been seared, return it to the pot and season with salt and black pepper.
Boil a medium pot of water over high heat. Once boiling, remove from heat and add the chiles, garlic, tomatoes, and onion. Allow the chiles and vegetables to soak in the boiled water for 15-20 minutes or until soft.
Use a slotted spoon to remove the softened chiles and vegetables from the pot and add them to a blender along with 1 cup of the cooking water. At the same time, add 1/2 cup of chicken broth plus the dried oregano, chicken bouillon, and dried cumin.
Blend until smooth.
Strain the sauce into the pot with the beef, gently tapping the strainer on the rim of the pot to encourage the liquid to go through.
When only pulp remains in the strainer, add it back to the blender with the remaining ½ cup of broth.
Blend again until smooth.
Strain it back into the beef, using a wooden spoon to push as much liquid out through the strainer. Discard any leftover pulp.
Set the pot over medium-high heat and bring to a simmer, then reduce heat to low, add the bay leaves, and cover with a lid.
Simmer low and slow for 1-2 hours or until the meat is tender and easily pulled apart with a fork. If the sauce is too thin, remove the lid and continue to cook until it thickens to your liking. If the sauce is too thick, add additional broth to maintain your desired consistency.
If the sauce is too spicy or acidic, season to taste with additional salt, pepper, or a pinch of sugar to balance the flavors.