Vietnamese Cajun Shrimp Boil My Familys Favourite

Ingredients

• 8 cups (1.9L) chicken broth
• 2 cups (475ml) water
• 1 large onion, roughly chopped (about 225g)
• 6 cloves garlic, smashed
• 4 inches (10cm) ginger, peeled and sliced
• 3 stalks lemongrass, bruised
• 2 tablespoons (30ml) fish sauce
• 2 tablespoons (30ml) Cajun seasoning (e.g., Tony Chachere's)
• 1 tablespoon (15ml) soy sauce
• 1 tablespoon (15ml) brown sugar
• 1 teaspoon black peppercorns
• 1/2 teaspoon cayenne pepper (optional, for extra heat)
• 2 pounds (900g) large shrimp, peeled and deveined (keep tails on)
• 1 pound (450g) andouille sausage, sliced into 1-inch pieces
• 6 small red potatoes, halved
• 4 ears of corn, shucked and cut into halves or thirds
• 1 pound (450g) crawfish (optional, if available)
• 1 bunch scallions, roughly chopped, for garnish
• Lime wedges, for serving