Wash and scrub mussels well. With a sharp knife, scrape off the poisonous beards and filaments at the joints of the shell. Wash again.
Place mussels in a pan with water to cover and boil for 30 minutes. Drain mussels and prise open shells with the edge of a sharp knife. Rinse mussels in fresh water and drain.
Heat 2 tsp oil in a pan, add onions and fry till brown. Reduce heat, mix in green chillies, ginger and curry leaves, and fry for 2 minutes.
Add mussels, spice powders and salt, and fry, stirring constantly, till completely dry. Remove from heat and set aside.
Mix flour with ¾ cup water and knead to a soft, pliable dough. Pinch off lime-sized potions of dough and roll into rounds, 10-cm in diameter.
Place 1 tbsp filling in the centre of each round and fold over edges to cover filling and form a square. Press dough lightly to seal.
Heat 1 cup oil in a kadhai and deep fry pastries and fold over edges to cover filling and form a square. Press dough lightly to seal.
Heat 1 cup oil in a kadhai and deep fry pastries in batches till golden brown. Drain and serve.
Note: Discard any mussels that are not tightly shut.
Variation: Minced chicken, mutton, beef or crabmeat can be substituted for mussels.
