Put, chicken stock, lime leaves, ginger, fish sauce and lemon juice into a saucepan. Bring to boil, stirring all the time, then add the coconut milk and finely sliced chicken. Continue to cook over a high heat until the chicken is just cooked, about 2 – 3 minutes depending on size of chicken strips.
Crush or finely chop the chilli and add to the soup with the coriander leaves. Cook for just a few seconds and serve immediately.