Ingredients

• 1 cup chiles de arbol, stemmed
• 1 1/2 cups cider vinegar
• 2 tablespoons minced onion
• 1 tablespoon minced garlic

Instructions

1. For a milder puree, rub chiles between your palms to remove most of the seeds. Chop chiles coarsely with a knife or in food processor. Put them in a bowl and pour vinegar over. Cover and refrigerate overnight.
2. Add onion and garlic to the chiles and either cover the bowl with plastic and microwave on HIGH for 1 minute, or put them in a saucepan over medium-high heat; cover, and simmer for 3 minutes. Let cool slightly, then puree in a blender until very smooth. Let cool.
3. Store in an airtight container for up to 1 month.