Tekwan/Fish Soup

My mother often cooks Tekwan, a fish soup made from fish paste and tapioca flour, for family and relatives. She uses always fresh Tenggiri fish/Mackerel to make Tekwan, served with vermicelli/rice noodles, shrimps, dried Lilies, dried black mushroom and Bengkuang/Jicama/ Yam Bean (Pachyrhizus erosus). I couldn´t follow exactly like her recipe because I used frozen fish and different type of mackerel fish. Bengkuang/jicama is rarely available here in Asia stores.

Ingredients:
for fish balls (not really look like balls):
500 g pangasius fillets, minced
400 g spanish mackerel (remove all skin & bones), minced
100 g tapioca flour
50 ml water
3 white eggs
salt to taste

for the prawn stock:
300 g whole raw tiger prawns, remove the heads and shells from the prawns (boil with 1 l water) and cut the prawns
2 l water
8 garlic cloves, sliced, fried then grinded
salt and ground white pepper to taste

to serve:
25 g dried black mushroom (Auricularia Auricula Judae), soak in hot water then drain
50 g bunga sedap malam/dried Lilies flower, soak in hot water then drain
2 tbsp chopped celery

directions:
for the fish balls: mix the ingredients in a food processor or just stir with a fork and make sure all ingredients mixed well. Boil 2 litres water in a large saucepan, reduce heat. Spoon about a half tablespoon of mixture, form balls by using two tablespoons. Pour the fish mixture spoon by spoon into water.
for the prawn stock: boil 1 litre water together with the heads and shells of prawns. Sift the prawn stock then discard the heads and shells of the prawns. Pour the prawn stock into fish balls soup. Add prawns, garlics. Seasoning with salt and pepper. Keep them simmer for a while then add mushrooms and dried lilies flower.
Serve immediately with rice noodles, chopped celeries and sambal Chillies.
P.S: my dear friend Mutiara, those are two bowls that you gave me at the Hamburg Airport last year. Thank you.