Layer all the ingredients except the ginger beer over ice in a Collins glass. Add ginger beer to top, and garnish with a rhubarb ribbon. Mix with your straw before enjoying.

Makes 2.5 cups, enough for 40 drinks.
(Recipe may be halved.)

Combine all the ingredients in a medium pot over high heat. Let it come to a boil, stirring occasionally, then remove it from the heat and let the mixture steep for 30 minutes. Strain  the liquid through a fine-mesh sieve into a jar, pressing the solids to extract as much syrup as possible. Seal and store extra syrup in the refrigerator for up to one month.