Cover dried chiles with water in small saucepan and bring to a boil. Simmer for about 10 minutes, then remove from heat and let sit for about an hour.

Drain chiles and place in blender or food processor with the salt and garlic. Purée the mixture and add the lemon juice, a little at a time. If the mixture is too dry, add additional lemon juice as necessary.

Pack the sauce in a clean jar and add enough olive oil to just cover. Cover and refrigerate, mix well before using.