Prepare ingredients: Cut fish into chunks; mince garlic and grate ginger.
Cook the curry: Heat oil in a pan. Add curry paste, garlic, and ginger, cooking briefly. Add fish, cooking gently until lightly flaked.
Simmer: Stir in coconut milk, lime juice, zest, salt, pepper, and optional fish sauce. Simmer until slightly thickened, about 10-15 minutes.
Prepare jasmine rice: Rinse rice, then boil with water and a pinch of salt. Reduce heat, cover, and simmer 15-20 minutes until tender.
Serve: Fluff rice with a fork. Serve curry over rice, garnished with fresh cilantro and additional lime zest if desired.