Prepare your sausage casing by rinsing it in warm water to remove excess salt, then set aside in a bowl of water. Meanwhile, in a large mixing bowl, combine the minced pork shoulder and pork fat, ensuring they are evenly distributed. The pork fat gives Sai Ua its rich, juicy texture.

In a mortar and pestle (or a food processor), combine the lemongrass, galangal, turmeric, garlic, shallots, cilantro root, and kaffir lime leaves. Pound or blend until you achieve a smooth paste, as this aromatic mix forms the foundation of the sausage’s flavour.

Add the red curry paste to the aromatic mixture, then stir in the fish sauce, sugar, salt, and ground white pepper. Mix well, ensuring the flavors are thoroughly combined. Adjust the seasoning with extra fish sauce or sugar if you prefer a stronger or sweeter taste.

Combine the aromatic paste with the minced pork and fat. Use your hands to knead and mix the ingredients, ensuring the paste is evenly spread throughout the meat. Kneading for several minutes will help bind the sausage mixture, giving it the ideal consistency.

Take the prepared sausage casing and tie one end. Using a sausage stuffer or a funnel, carefully stuff the pork mixture into the casing, being careful not to overfill. After filling, tie off the other end of the casing.

Twist the sausage into sections, around 10-12 cm in length, depending on your preferred size. You can tie off each section with string or simply twist the casing.

Preheat your oven to 180°C (350°F). Place the sausages on a wire rack with a tray beneath to catch any drippings. Roast in the oven for 25-30 minutes, turning them occasionally to ensure they cook evenly and develop a golden-brown crust.

Once cooked, let the sausages rest for 5 minutes before slicing. Serve the Sai Ua hot with sticky rice, fresh herbs, and a side of Nam Prik Noom (Northern Thai chili dip) for an authentic Northern Thai experience.