Add all ingredients into a mixing glass with ice and stir until well-chilled.
Strain into a rocks glass over fresh ice.
Garnish with a thyme sprig.
*Hibiscus-thyme shrub: Combine 1 cup white sugar and 1 cup white wine vinegar in a saucepan, and stir over low heat until sugar is dissolved. Add 1/2 cup dried hibiscus flowers, mix well, and add 24 thyme sprigs. Remove from the heat and let cool, then chill overnight. Strain out solids, then transfer to glass syrup bottles.