To make Lemongrass Syrup: In a saucepan over medium heat, dissolve 1 cup of granulated sugar into 1 cup of water. Cool to room temperature, and pour the syrup into a blender with 4 stalks of lemongrass. Blend the mixture and strain through chinois or cheese cloth. Store in an air-tight container in the refrigerator.
Ginger and chiles give this Southeast Asian rendition its aroma and spice, while lemongrass lends the soup a seductive floral note. By swapping the traditional seasonings for more exotic ones, you achieve a soup that's just as soothing as the original but with nuanced layers of flavors.