Turn the casing inside out and rub with 1/4 cup salt and a little water gently but very well.
Rinse again and again until it become odorless.
Then turn it right side out and squeeze out the excess water.
Combine softened dried chilies, 1/2 teaspoon salt, lemon grass, cilantro roots, Kaffir lime zest, galanga, garlic and onions in a blender and grind to a paste.
Mix the chili paste, pork, Kaffir lime leaves, cilantro leaves and fish sauce well.
Tie a knot a one end of the casing and stuff with the pork mixture.
Tie another knot to close.
Poke a few holes with a clean needles where the bubbles are present inside.
Charbroil or fry over medium-low heat until golden brown and fully cooked.
Poke a few holes while cooking to prevent rupturing.