A while back, researching salsas for birria; I chanced to find on the 'net a recipe at a sports fishing site. The poster was giving his uncles recipe. I put the words and the URL into my recipe book, but when I returned to it in August of 2020, the entire website is gone. And no record at archive.org, either.
It was while reading this recipe that the gist of Mexico's culinary King came to me. It was the act of placing the ingredients in dying embers. That is, no direct flames that gave the smokey and spicy flavor.
If I recall I was researching salsas for birria.
The recipe will be supplied, below. A caveat: the original recipe, gave no quantities for the ingredients. But as this recipe comes from a road side taco stand, the quantities would not be large. Certainly larger than for a small family, but the right amount for a party.
a esa carne le hace una buena salsa mi tio vende
tacos al pastor y el exito es su salsa le voy a pasar la receta las
cantidades no las se perdon
chile morita seco
chile de arbol seco
jitomate
tomate
sal
cebolla
ajo
todo esto va herbido el jitomate es muy poco lleva mas tomate k jitomate pero en serio keda deliciosa y perdon por la expicacion pero yo solo veo komo la hace nunka la he hecho solo me la komo jajaj
That is all there is to it. No call for liquid, but my instinct is they used water. All are whirled in a blender until smooth.
The secret here is to have a small fire of burning embers and embed the ingredients in it, being careful no to scorch the items too much. I guess it would take some practice to perfect.