In a medium pot, heat vinegar, sugar, thyme and juniper berries over medium-high heat and bring to a boil.
Set pears in a large bowl and pour boiled vinegar mixture over them. Cool to room temperature, then cover and refrigerate. Let the shrub steep 2 -4 days before straining. Our patience ran out after 2 days, but if you can wait the full 4 days, the pear flavor will be more pronounced.
Refrigerate shrub in a sealed container until ready to use.
To prepare the Juni-pear Gin and Tonic, fill a glass with ice and add gin, pear shrub and tonic. Garnish with a couple sprigs of thyme and slices of pear.
Recipe by Allons-Eat! at https://www.allonseat.com/pear-shrub/