Fresh serrano chiles give this vinegar from Dave DeWitt's "The Complete Chile Pepper Book" its crisp flavor. Also Try:Piri Piri Oil
Place vinegar, oregano, garlic, and chiles in a large jar; cover and let stand in a cool, dark place 3 to 4 weeks. Strain through a fine mesh sieve; discard solids and transfer liquid to sterilized jars. Vinegar can be stored at room temperature.