Beyond fish and prawns, the seafood woven into daily life in Nha Trang is the shelled kind: clams, blood cockles, scallops, sweet snails, oysters. They sit in trays at the front of the shop; you pick, then they cook.
The usual treatments are steaming with lemongrass, grilling with spring-onion oil, or stir-frying with tamarind or garlic. Steamed silk clams are the simplest dish and the honest test of freshness — lemongrass and chilli and nothing to hide behind.
This is plastic-stool dining, ordered a small plate at a time. The one rule is the same as anywhere seafood is sold: agree the price per kilo or per plate before you order.