Hazırlanışı
1Begin by preparing the Pasilla chiles. Remove stems and seeds from the Pasilla chiles. Heat a dry comal or skillet over medium heat and toast the Pasilla chiles for 30-60 seconds per side until fragrant, being careful not to burn them. Place the toasted Pasilla chiles in a bowl and cover with hot water. Let them rehydrate for 20 minutes.
2While the chiles rehydrate, prepare the sauce base. Place the Tomatillos, White onion, and Garlic cloves on a baking sheet. Roast under a broiler or in a hot oven (200C/400F) for 15-20 minutes, turning occasionally, until softened and slightly charred.
3Drain the rehydrated Pasilla chiles, reserving a small amount of the soaking liquid. Transfer the Pasilla chiles, roasted Tomatillos, roasted White onion, and roasted Garlic cloves to a blender. Add the Chicken broth and Salt. Blend until very smooth, adding a little reserved chile soaking liquid if needed to achieve a pourable consistency.