Steamed Black Sea Bass with Water Spinach and Cilantro

Crisp water spinach stems contrast with tender leaves and soft steamed fish in this light, simple dish—which needs no more than scented rice to make a meal. The best coriander has its roots intact. If you find it, trim these and scrub with a brush, then mince and add with the sliced spinach stems. I like roasted peanut oil (Loriva is a widely available brand), which is more intense than oil from raw peanuts. If it is not available, add a soupçon of Asian sesame oil to regular peanut oil.