Cut the ling fillet into 1 1/2-inch/4 cm pieces, place in a bowl and set aside.
Put the white heads of the spring onions
(reserving the stalks) and garlic in a mortar and pound to a paste. Add the turmeric
, curry powder, yoghurt, fish sauce, sugar, 2 tablespoons oil, and a 1/3 of the dill, roughly chopped, to the fish and mix well.
Cover and marinate in the refrigerator for 1 hour.
Thinly slice 4 of the green spring onion stalks.
Heat a large frying pan
over medium heat, add the remaining oil, then fry the fish fillets
on one side for 30 seconds.
Turn the fillets over, add the fish stock
for 3 to 5 minutes, until the fish is cooked through. Remove the fish and squeeze over the juice from the lemon.
Mix the bean sprouts
, sliced spring onion, remaining dill
and vermicelli together.
Place into bowls and spoon over the fish fillets and sauce.