Remove stems and seeds from ancho chiles and guajillo chiles. Place the chiles in a bowl and cover with hot water. Let them rehydrate for 20 minutes until softened.
2
Drain the rehydrated chiles and place them in a blender with garlic cloves, white onion, cumin powder, Mexican oregano, black pepper, and sea salt. Add a small amount of the beef broth if needed to create a smooth, thick paste.
3
Pat the beef chuck roast completely dry with paper towels. Generously rub the chile paste all over the beef chuck roast, ensuring it is fully coated.
