Shellfish in Vietnam is very popular. This type of clam is one of the Vietnamese's favorite. They can be boiled, fried, steamed, or can be eaten raw. Pry one open and grab the meat with your chopsticks or a shrimp fork. You'll see a little sack of hemoglobin that is a very dark red. This is why they're called blood cockles. Dip the whole thing in the lime and pepper mix. They are a great appetizer and they go well with beer. The Vietnamese love food that involves some work. It adds to the social aspect of dining out with friends. Having to pry these little guys open allows you to eat slower and get more conversation (and beer) in. Often, these will come cooked with chili, tamarind, or lemongrass.