Ingredients
Method
1.Put vegetable stock in a large saucepan. Shell the prawns and add heads and shells to the stock. Bring to the boil, then turn down to a simmer. Add chilli, lemongrass, ginger and garlic and cook for 25 minutes on low heat.
2.Pour broth through a fine sieve into another pot. Bring back to the boil, turn down to a simmer, then add the prawns, green beans and beansprouts and cook for 1 minute. Remove from heat and stir in baby spinach. Season with lime juice and fish sauce. Ladle into bowls and serve with a drizzle of sesame oil.
