Vietnamese lemongrass coconut seafood soup

My Vietnamese lemongrass coconut seafood soup has a mouthwatering medley of spot prawns, mussels, and clams bathed in an aromatic and rich broth.

With spot prawn season going strong, I’m sharing one of our favorite seafood recipes, Vietnamese lemongrass coconut seafood soup. This was adapted from my mom’s lemongrass coconut prawn noodle soup which I’ll share later. It has three different types of shellfish, spot prawns, mussels, and clams in a fragrant and flavorful broth. We usually make this for lunch after coming home from the Tuna Harbor Dockside Market while the spot prawns are still fresh.

Ingredient notes

• Lemongrass: much of the lemongrass’s flavor is concentrated in its lower, cane-like stalks. Look for firm, pale-green stalks with fat, bulbous bottoms. Trim off the spiky tops and the bases and crush the stalks with the side of a knife to release their aromatic oils.
• Makrut lime leaves: are used often in Southeast Asian cooking. They are one of the most aromatic herbs and a wonderful addition to many soups, curries, and desserts. We grow our own but you can find them in the fresh herb section at many Asian grocery stores. Look for fresh makrut lime leaves that are dark green, shiny, and without any browning or yellowing. 
• Coconut cream:  for this recipe use coconut cream, not coconut milk. The flavor you get from coconut cream is much richer. My favorite brands are Savoy and Aroy-d.
• Shellfish stock: I used a basic homemade shellfish stock made from simmering a pound of prawn heads and tails with 4 cloves of garlic, 4 cups of water, and letting the volume reduce by half over 30 minutes. You can double or triple the amount to make what you need. If you don’t have time to make your own stock, get a quality stock from your fishmonger or local supermarket.
• Palm sugar: palm sugar is very popular in Vietnamese cooking. It contains less glucose and has a lower glycemic index compared to regular sugar. If you can’t find palm sugar, you can also substitute with coconut sugar, rock sugar, or light brown sugar. 
• Fish sauce: use a quality fish sauce. Some of my favorite brands are Three Crabs, Flying Lion Premium Fish Sauce, and Red Boat Fish Sauce.

Tips for prepping the shellfish

I used spot prawns, mussels, and clams for this recipe but feel free to substitute with some of your favorite shellfish.

• Spot prawns: with live spot prawns you have to work fast or they will spoil. Immediately get them into a cooler or on ice after you purchase them. Avoid putting them in tap water or the chlorine in the water will hasten their death. If you’re not cooking them right away, remove their heads and leave the tail on ice. Freeze the prawn heads if you’re not using them right away. Put the tails on ice, cover them with a cloth and keep them in the fridge for up to two days until you’re ready to cook. Spot prawns have an enzyme in their brain that starts spreading as soon as they die and turns the flesh soft and mushy. Before cooking, simply give them a quick rinse in water and let them dry on a few sheets of paper towel.
• Clams: I usually buy manila clams or littleneck clams.  It’s important to use fresh live clams for the best taste. Pick clams with shells tightly closed. If the shells are open, give them a quick tap. If they don’t close, discard them. Just before cooking, soak the clams in a large pot of cold water for 30 minutes. Drain well, being sure to remove all sand. 
• Mussels: Pick ones that small, black, and glistening and you’ll be rewarded with a sweet, tender, and briny taste.  As soon as you get home, rinse them in very cold water which makes their shells shut tightly. Discard any that are open, broken, or cracked. While you’re checking them, remove their beards by gently pulling and twisting at the same time.  If you’re not ready to cook them, put the prepped mussels in a dry bowl covered with a damp towel and refrigerate.

Tips for making the soup

• Use the freshest shellfish you can find. They are the heroes of this Vietnamese lemongrass coconut seafood soup.
• Crush the makrut lime leaves and lemongrass with the back of your knife to release their aromatic oils.
• Have all the ingredients measured and ready to go.
• Cook the prawns with shell on to prevent them from shrinking and overcooking.
• Cook the mussels and clams until they open.  Discard any clams and mussels that didn’t open.
• Taste and adjust your seasoning at the end with additional fish sauce, sugar, or stock.

In 30 minutes you have a steaming pot of Vietnamese lemongrass coconut seafood soup with the most sumptuous spot prawns, mussels, and clams. Peel the prawns with your hands, pick the mussels and clams from the shells, and scoop up the fragrant and rich coconut broth as you pop those delicious morsels in your mouth. My kids love to dunk freshly toasted baguette into the broth along with the shellfish. You can also enjoy the seafood soup with a bowl of jasmine rice. Whatever way you enjoy it, expect a whirlwind of aromas and flavor from this fresh and warming Vietnamese lemongrass coconut seafood soup.  

For more seafood inspiration, check these recipes: Vietnamese tamarind prawns, Vietnamese prawn and sweet potato fritters, Vietnamese lemongrass beer steamed clams.