Hazırlanışı
1Place the guajillo chiles, ancho chiles, and arbol chiles in a bowl. Cover them with 500g of hot water and let them rehydrate for 20 minutes until softened. Drain the chiles, reserving the soaking liquid.
2While chiles rehydrate, heat a comal or heavy skillet over medium-high heat. Place the halved Roma tomatoes, roughly chopped white onion, and garlic cloves on the comal. Roast them, turning occasionally, until softened and slightly charred, about 10-15 minutes.
3Transfer the rehydrated chiles, roasted Roma tomatoes, roasted white onion, and roasted garlic cloves to a blender. Add 200g of the reserved chile soaking liquid and blend until very smooth. Strain the mixture through a fine-mesh sieve into a bowl, pressing on the solids to extract all liquid. Discard the solids.