Thai red curry mussels - Eat Well Recipe

1 TbspCooking oil1 TbspThai red curry paste, heaped (Main)1Finely sliced red onion330 gCoconut milk1 cupWater2 TbspBrown sugar2Limes, juiced1 tspFish sauce2 kgsMussels, scrubbed and debearded (Main)1 small bunchFresh coriander2Limes, in wedges, to garnish