Remove stems and seeds from dried chiles, then toast briefly in a dry skillet until fragrant.
Place toasted chiles in a bowl, cover with hot water, and soak for 15 minutes until softened.
Blend softened chiles with onion, garlic, cumin, oregano, salt, and some soaking liquid until smooth.
Heat oil in a large pot and brown seasoned beef in batches, then set aside.
Return beef to the pot, pour in chile sauce, and add broth or water to mostly cover.
Bring to a gentle boil, reduce heat, cover, and simmer for 1½ to 2 hours until tender.
Taste and adjust seasoning until the sauce is deep red and well balanced.
Serve hot with Mexican rice and warm flour tortillas.