Slice lemongrass stalk and cut four slices of lime peel (green part only).

Put water, lemongrass, and lime peel into a pot.

Bring to a boil and simmer for 5 minutes.

Discard lemongrass and lime peel.

Deseed and slice the chili pepper.

Add chili, ginger paste, bouillon cube, and coconut milk to the pot.

Simmer gently.

Fry the chicken pieces in a frying pan until done.

Add the fried chicken to the pot along with fish sauce.

Simmer for a few minutes.

Chop tomatoes and slice spring onions.

Add tomatoes and spring onions to the pot and bring briefly to a boil again.

Stir in chopped cilantro just before serving.