In a saucepan put:
7 Guajillo Peppers.
5 Ancho Peppers.
nnd enough water to cover the chilies.
Bring the saucepan water to a boil over high heat and leave the chilies cooking in the boiling water for about 5 minutes, until they soften.
Transfer from the saucepan to a blender, with a kitchen spoon, the chilies that were cooked.
Also add in the blender:
1/2 Onion.
1 Garlic clove.
1 teaspoon of Cumin.
1 teaspoon of Oregano.
1 tablespoon of White Vinegar.
Pepper to taste.
1/4 tablespoon of Salt.