Heat oil in a deep cast iron pan (or a medium dutch oven) over medium heat. Add the beef and let it brown for about 10 minutes, as you stir every so often to prevent burning. (If the beef is crowded in the pot, brown it in batches.)

Reduce the heat to low and let it continue to cook as the liquid (created by the beef) reduces.

In the meantime, heat a medium size pot of 5-6 cups of water over high heat and bring it to a boil.

Add the guajillo, pasilla and ancho chiles to the pot and let them boil for 10 minutes. Remove the pan from the heat.

Strain the chiles from the water (reserve 1 cup of the water) and add the chiles to a blender, or food processor, along with 1 cup of the reserved water from the pan and blend until smooth.

Strain the sauce, through a strainer, into the pot with the beef. Add in the beef broth, bay leaves, oregano, cumin, coriander, salt and pepper and stir to combine.

Bring the heat back up to medium and let it boil for 5 minutes. Reduce the heat to low and cover the pan with a lid slightly offset to let a bit of the steam escape. Let it cook for 45 minutes.

Add the onion and garlic and stir to combine. Let it continue to cook for another 15 to 30 minutes, or until the onions have become soft and the sauce reaches your desired thickness. (If your sauce becomes too thick, add a little extra water that the chiles cooked in, as needed.)

Remove the pan from the heat and serve as desired. We serve ours over Mexican rice, with corn tortillas, and freshly chopped cilantro.