Heat the oil in a soup pot over medium-high heat. Add the ginger and chili sauce and cook 30 seconds. Add the stock and bring to a boil. Add the rice, reduce heat, and simmer for 15 to 20 minutes, or until the rice is tender.
Add the remaining ingredients, except the prawns. Simmer for 5 minutes, stirring occasionally. Add the prawns and cook 3 minutes, or until just cooked through. Ladle into bowls, garnish with chopped cilantro and serve.