1 3/4 oz. rum (light or dark)
3/4 oz. Royal Rose Tamarind Syrup
1/2 oz. fresh lime juice
3 slices ginger, muddled
1/2 dropper-full of The Bitter End Thai Bitters
Shake ingredients and strain into a tall glass filled with ice. Top with soda water. Garnish with a lime wedge and serve with a straw.