Kia Ly Dickinson of Miami, Florida, writes: "This fragrant soup is so good you will be freaking out. It can be served hot or cold, with rice. The recipe is an ode to my homeland, Vietnam, and I'd like to share it with my new friends in America."
This recipe calls for fresh lemon verbena, but you can substitute 1 stalk of fresh lemongrass if lemon verbena is unavailable. Both ingredients are sold at specialty produce markets, but lemongrass is also sold at Asian markets and some supermarkets, so it may be easier to find. If using lemongrass, discard 1 or 2 outer leaves, then thinly slice lower 6 inches of stalk. Finely chop, then sauté along with chiles and garlic.