In a small saucepan place the tomatillos, onion, garlic and the jalapeño chiles cover with water and cook over medium heat, until tomatillos and chiles change color. Remove from heat, reserve the cooking liquid and set aside to cool.
Place tomatillos, onion, garlic and chiles in the blender, process for a few seconds until smooth, add the cilantro, process again on low until the cilantro is coarse and well incorporated.
Add the oil to a small saucepan, add the blended salsa and bring to a gentle simmer for 8 minutes, or until thickens, season with salt. Add reserved cooking liquid if needed.
Recipe reprinted with permission © 2021 Iliana de la Vega