1Remove stems and seeds from Guajillo chiles and Ancho chile. Toast them lightly in a dry pan over medium heat for 1-2 minutes until fragrant, being careful not to burn. Transfer toasted chiles to a bowl and cover with hot Water for 15 minutes to rehydrate.
3In a blender, combine the rehydrated Guajillo chiles, Ancho chile, chopped Roma tomatoes, chopped White onion, and chopped Garlic cloves with 100g of Water. Blend until smooth. Strain the mixture through a fine-mesh sieve into a bowl, pressing firmly to extract all liquid. Discard the solids.