Hazırlanışı
1Preheat a comal or heavy skillet over medium heat. Toast the guajillo chiles and chile de arbol for 1-2 minutes, turning frequently, until fragrant but not burnt. Immediately transfer the toasted chiles to a heatproof bowl and cover with hot water. Let them rehydrate for 15-20 minutes.
2On the same comal or skillet, roast the tomatillos, half of the white onion, and the garlic cloves. Turn them occasionally until softened and lightly charred in spots, about 10-15 minutes.
3Drain the rehydrated guajillo chiles and chile de arbol. Transfer them to a blender along with the roasted tomatillos, roasted white onion, roasted garlic cloves, the remaining raw white onion, and the water. Blend until completely smooth. If needed, add a small amount of additional water to achieve a pourable consistency.