Image credit to: Joshua Graveline for Boston Organics
Video
Combine first 3 ingredients in a clean 1-quart glass jar. Add vinegar, salt, and sugar. Cover; shake until sugar and salt begin to dissolve. Refrigerate for at least 3 days, shaking once a day. DO AHEAD Can be made 1 month ahead. (The flavor mellows the longer the mixture pickles.) Keep chilled.