1Begin by preparing the dried guajillo chiles, dried ancho chiles, and dried arbol chiles. Remove the stems and seeds from all chiles. Heat a comal or dry skillet over medium heat and toast the chiles for 1-2 minutes per side until fragrant, being careful not to burn them. Transfer the toasted chiles to a bowl and cover with hot water, allowing them to rehydrate for 20 minutes.
2While the chiles rehydrate, peel the garlic cloves and roughly chop 100g of white onion. In a blender, combine the rehydrated chiles (reserving a small amount of the soaking water), garlic cloves, chopped white onion, white vinegar, lime juice, ground cumin, dried Mexican oregano, black pepper, and 10g of salt. Blend until a smooth paste forms, adding a little of the reserved chile water if needed to achieve a pourable consistency.