Place a comal over medium heat. Toast the chiles de arbol for a few seconds until fragrant. Be careful not to burn them.
Roast the tomatillos, onion, and un-peeled garlic cloves until charred and cooked through. Let cool, then blend with toasted chiles de arbol, raw garlic, cilantro, and salt until smooth. Pour into a bowl and stir in the diced avocado.
Course: Sides
Cuisine: Mexican
Keyword: Green Salsa, Mexican Food, Salsa Taquera, Salsa Verde, Tacos