Toast chiles de arbol on a comal or in a frying pan until they are deeply browned, like the color of chocolate. Remove chiles and add garlic to the comal and brown on all sides.
In a molcajete or a food processor, add chiles, garlic, lime juice and salt and process until roughly chopped.
Start adding water slowly, making sure to incorporate all the water added before adding more. Salsa should be the consistency of pulpy orange juice when done. This can take up to 2-3 minutes in a food processor.
Adjust seasoning if necessary and serve.