Thai Seafood Glass Noodles with Prawns or Crab: A Clay Pot Classic

Thai seafood glass noodles, known as goong ob woon sen with prawns or pu ob woon sen with crab, is a beloved dish of chewy glass noodles, succulent seafood, and aromatic ginger, all steamed together in a clay pot. The noodles soak up a savory-sweet sauce infused with coriander roots and garlic, resulting in a glossy, fragrant one-pot meal that is both comforting and elegant.

What Are Thai Glass Noodles?

Glass noodles, also called cellophane noodles or bean thread noodles, are made from mung bean starch. When cooked, they turn translucent and have a springy, slightly slippery texture. Unlike wheat or rice noodles, they have a neutral taste and easily absorb the flavors of the liquids they are cooked in. In this Thai dish, the noodles are not boiled separately; instead, they are soaked in water until pliable, then steamed in the clay pot with the seafood and sauce. This method allows the noodles to drink in all the aromatic liquids, becoming deeply flavorful.

How to Make Thai Crab Glass Noodles (Pu Ob Woon Sen)

This dish features crab, often blue swimmer crab, cut into pieces. The crab's sweet meat and rich tomalley infuse the noodles with a delicate briny flavor. The key is to arrange the ingredients in the clay pot so the crab sits on top, allowing its juices to drip down into the noodles as it cooks.

Ingredients

• 200g dried glass noodles (mung bean vermicelli)
• 1 large blue swimmer crab (about 500g), cleaned and cut into pieces
• 4-5 cloves garlic
• 2 coriander roots (or 1 tsp coriander stems, finely chopped)
• 1 tbsp ginger, julienned
• 2 tbsp oyster sauce
• 1 tbsp soy sauce
• 1 tsp dark soy sauce (for color)
• 1 tsp sugar
• 1/2 tsp white pepper
• 1 tbsp cooking oil (vegetable or peanut)
• 1 cup chicken stock or water
• 2-3 spring onions, cut into 2-inch pieces
• Fresh coriander leaves for garnish

Step-by-Step Method

1. Soak the noodles: Place the dried glass noodles in a bowl of warm water for 15-20 minutes until soft and pliable. Drain well and set aside.
2. Make the sauce: Pound the garlic and coriander roots in a mortar and pestle until a rough paste forms. In a small bowl, mix the oyster sauce, soy sauce, dark soy sauce, sugar, and white pepper. Stir in 1-2 tablespoons of water to dissolve.
3. Arrange the clay pot: If using a traditional clay pot, soak it in water for 10 minutes before use (if unglazed). Heat the oil in the clay pot over medium heat. Add the garlic-coriander paste and ginger, stir-fry until fragrant, about 30 seconds. Add half of the sauce mixture and stir.
4. Layer the noodles: Add the drained glass noodles to the pot, tossing gently to coat with the sauce. Pour in the chicken stock or water. Place the crab pieces on top of the noodles, shell side down. Drizzle the remaining sauce over the crab.
5. Steam: Cover the pot with a lid and cook over medium-low heat for 10-12 minutes, or until the crab is cooked through and the noodles have absorbed most of the liquid. Avoid stirring to prevent breaking the crab pieces.
6. Finish and serve: Remove from heat, scatter spring onions and coriander leaves on top. Serve directly from the clay pot.

How to Make Thai Prawn Glass Noodles (Goong Ob Woon Sen)

The prawn version is quicker and easier; large prawns are used, often with heads and shells on for maximum flavor. The prawns release their juices into the noodles, creating a rich, sweet taste.

Ingredients

• 200g dried glass noodles
• 8-10 large prawns (shrimp), shell-on, deveined
• 4-5 cloves garlic
• 2 coriander roots
• 1 tbsp ginger, julienned
• 2 tbsp oyster sauce
• 1 tbsp soy sauce
• 1 tsp dark soy sauce
• 1 tsp sugar
• 1/2 tsp white pepper
• 1 tbsp cooking oil
• 1 cup chicken stock or water
• 2-3 spring onions
• Fresh coriander for garnish

Step-by-Step Method

1. Soak the noodles: Soak glass noodles in warm water for 15 minutes, drain, and set aside.
2. Make the sauce: Pound garlic and coriander roots into a paste. Mix with oyster sauce, soy sauce, dark soy sauce, sugar, and white pepper.
3. Sauté aromatics: In a clay pot or heavy-bottomed pot, heat oil over medium heat. Add garlic-coriander paste and ginger, stir-fry until fragrant.
4. Add noodles and liquid: Add half the sauce, then the noodles, tossing to coat. Pour in stock or water. Arrange prawns on top. Drizzle remaining sauce over prawns.
5. Cook: Cover and cook over medium-low heat for 8-10 minutes until prawns turn pink and curl, and noodles are tender.
6. Serve: Garnish with spring onions and coriander.

Understanding the Key Ingredients

Glass Noodles: The Star

Glass noodles made from mung bean starch become clear and chewy when cooked. They differ from rice vermicelli, which are white and softer. Their neutral flavor makes them ideal for absorbing the rich sauces in this dish. When buying, look for bundles that are dry and brittle; after soaking, they should be pliable but not mushy. If you cannot find mung bean glass noodles, sweet potato starch noodles (often used in Korean japchae) are a good substitute, though they have a slightly chewier texture and a grayish tint.

Prawns vs. Crab

For a vegetarian alternative, you can use firm tofu or mushrooms, but the dish will lose its signature seafood sweetness.

Ginger and Coriander Roots: Aromatic Base

Ginger adds a warm, spicy note that cuts through the richness of the seafood. It is julienned into thin strips so it infuses the dish without overpowering. Coriander roots are a staple in Thai cooking, prized for their intense, earthy, citrusy flavor—more potent than the leaves. They are often pounded with garlic to form the foundation of marinades and sauces. If you cannot find coriander roots, use the lower stems of the coriander plant, which have a similar, though milder, flavor.

The Clay Pot: Traditional Cooking Vessel

A clay pot is traditionally used for this dish because it distributes heat evenly and retains it well, creating a gentle steaming environment that prevents the noodles from scorching. The porous nature of unglazed clay also allows some evaporation, concentrating flavors. If you don't have a clay pot, a heavy-bottomed saucepan or Dutch oven with a tight-fitting lid works well, though the subtle earthy aroma from the pot will be missing.

The Sauce: Savory, Sweet, and Umami

The sauce combines oyster sauce (for deep umami and slight sweetness), soy sauce (saltiness), dark soy sauce (color and a hint of molasses), sugar (balance), and white pepper (gentle heat). This mixture is similar to the base for many Thai stir-fried noodle dishes but used here in a steaming method, so the noodles absorb it completely.

Tips for Perfect Thai Seafood Glass Noodles

• Do not oversoak the noodles: They should be soft but still have a slight bite; they will finish cooking in the pot.
• Keep the shells on the prawns: The shells add flavor to the sauce and protect the delicate flesh from overcooking.
• Use a wide, shallow pot: This ensures even cooking and allows the seafood to sit on top of the noodles, so its juices drip down.
• Resist stirring: Stirring can break the seafood and make the noodles mushy. Gently shake the pot if needed.
• Serve immediately: Glass noodles continue to absorb liquid and can become overly soft if left too long.

Thai seafood glass noodles with prawns or crab is a dish that showcases the harmony of Thai flavors—sweet, savory, aromatic, and fresh. Whether you choose the delicate sweetness of prawns or the rich indulgence of crab, the chewy, flavor-soaked noodles are the ultimate comfort.