Peel and chop the ginger. Peel garlic and press lightly. Wash the chilli. Wash coriander and shake dry. Wash lemongrass and squeeze lightly. Put ginger, garlic, chilli, coriander and lemon grass in a large pot.
Pour on 5 litres of water. Add 1 tablespoon of salt. Bring to the boil covered and simmer at low heat for about 1 hour.
In the meantime prepare the remaining fondue ingredients and dips (see Red Tahina, Hot Plum Dip and Wasabiguacamole). Arrange on plates and in small bowls.
Season the Asian stock with oil and soy sauce. Pour through a fine sieve into two fondue pots. Bring to the boil again just before serving on the stove.
At the table, place fondue pots on suitable chafing dishes. Adjust the chef's sauce so that the stock simmers slightly. Cook the fondue ingredients in portions in the hot stock using the fondue forks and sieves.
Slices of lime are enough.