1. Pack jalapenos and onion into one clean 16-ounce lidded jar, or divide between two 8-ounce lidded jars.
2. Combine vinegar, water, sugar, salt, garlic, and peppercorns in a small saucepan and bring to a boil. Reduce heat to medium-low and simmer, stirring occasionally, until sugar and salt are dissolved, about 1 minute.
3. Pour hot liquid over jalapenos and onion, pushing down to submerge, and seal tightly. Let cool completely, then refrigerate for at least 2 days before using and up to 1 month.
Source: Hannaford fresh Magazine, July - August, 2017