To 5 cups of simmering water, add the washed tomatillos and fresh green chiles. Also add the 1/3 section of onion and 3-4 cloves of peeled garlic. Let ingredients cook at a steady simmer for 10 minutes or until tomatillos turn from bright green to an opaque color. Let ingredients sit off the heat for 10 minutes.

Using a slotted spoon, transfer salsa ingredients to the blender. Add the fresh cilantro, 3/4 cup of the cooking water and salt to taste. Some people like to use chicken bouillon powder to season and flavor their salsa. it's an option! Blend on high until smooth and pour back into pot you used to cook the ingredients in. Heat to medium until it begins to simmer. reduce heat slightly.

In a separate skillet, heat 1 tablespoon of oil(your choice), to medium heat. Add the diced onion and minced serrano pepper. Season lightly with salt and pepper and saute for 3-4 minutes. Pour in 1 1/4 cups of warm salsa verde into skillet. Stir well to combine and let it simmer for 2 minutes.